JP7762215B2 - Audio device, audio device control method and program - Google Patents

Description

The present invention relates to an audio device, a control method for an audio device, and a program.

Conventionally, DJ equipment such as DJ controllers have multiple decks, and while playing music on each deck, switching the audio output between the decks allows switching from one playing song to another. When switching songs on such DJ equipment, it is generally necessary to synchronize the tempos of the songs before and after the switch. In recent years, it has become common to switch between songs of different genres or songs with significantly different BPMs.
Therefore, assuming that the BPM is changed by about 20 to 30, a relative mode has been considered in which the tempo slider can be operated based on a relative position rather than an absolute position (see, for example, Non-Patent Document 1).

Serato DJ Pro User Manual (Serato) (https://support.serato.com/hc/ja/articles/227561947)

In the relative mode described above, by using the SHIFT button in combination, the tempo is adjusted based on the relative position of the tempo slider while the SHIFT button is pressed, and the tempo is adjusted based on the absolute position of the tempo slider when the SHIFT button is not pressed. Therefore, when executing the relative mode, the user must use both hands to keep the SHIFT button pressed, which creates the problem of being unable to simultaneously perform operations other than tempo adjustment, such as effect operation. Furthermore, if an operation error involving the SHIFT button occurs, such as pressing the wrong SHIFT button, abnormal sound output or a sudden change in sound output may occur.
Furthermore, in relative mode, it is difficult to intuitively and instantly grasp the state of the tempo adjustment depending on the position of the tempo slider. In particular, in relative mode, it is impossible to even grasp whether the current tempo is faster or slower than the original song.
SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an audio device that allows intuitive operation and highly operable tempo adjustment, as well as a method and program for controlling the audio device.

[1] An audio device equipped with a tempo slider that changes the playback speed of a song being played, the audio device comprising: an operation unit that accepts user operations that change the range of playback speed that can be changed by the tempo slider; and a setting unit that, upon accepting user operations by the operation unit, sets the range of playback speed that can be changed by the tempo slider in accordance with the playback speed at the time of user operation.
[2] The audio device described in [1], wherein the setting unit sets the range of change in playback speed by the tempo slider depending on the difference between the playback speed of the original song of the song being played and the playback speed at the time of user operation.
[3] The audio device described in [1], wherein the setting unit sets the range of change in playback speed by the tempo slider depending on the ratio between the playback speed of the original song of the song being played and the playback speed at the time of user operation.
[4] An audio device described in any of [1] to [3], wherein the operation unit further accepts a user operation to set a mode for synchronizing the tempos of at least two songs, and when the setting unit accepts a user operation to change the range of change after the mode is set, the setting unit sets the range of change according to the playback speed at the time of the user operation to change the range of change of the playback speed using the tempo slider.
[5] An audio device described in any of [1] to [3], wherein the operation unit accepts a user operation to set a mode for synchronizing the tempos of at least two songs, and the setting unit, upon accepting the user operation to set the mode, sets the range of change in playback speed using the tempo slider depending on the playback speed after the user operation to set the mode.
[6] A method for controlling an audio device equipped with a tempo slider that changes the playback speed of a song being played, the method including the steps of: accepting a user operation that changes the range of playback speed that can be changed by the tempo slider; and, upon accepting the user operation, setting the range of playback speed that can be changed by the tempo slider in accordance with the playback speed at the time of the user operation.
[7] A program for causing a computer to function as an audio device equipped with a tempo slider that changes the playback speed of a song being played, the program comprising: an operation unit that accepts user operations that change the range of playback speed that can be changed by the tempo slider; and a setting unit that, upon accepting user operations by the operation unit, sets the range of playback speed that can be changed by the tempo slider in accordance with the playback speed at the time of user operation.

According to the above configuration, in an audio device equipped with a tempo slider that changes the playback speed of a song being played, when a user operation is received to change the range of playback speed that can be changed using the tempo slider, the range of change is set according to the playback speed at the time of the user operation, allowing for intuitive operation and achieving highly user-friendly tempo adjustment.

1 is a schematic diagram illustrating an acoustic device according to an embodiment of the present invention. 1 is a block diagram showing a schematic functional configuration of an audio device according to an embodiment of the present invention; FIG. 10 is an enlarged view of the vicinity of the tempo slider in one embodiment of the present invention. FIG. 10 is another enlarged view of the vicinity of the tempo slider in one embodiment of the present invention. 3 is a flowchart illustrating a control method according to an embodiment of the present invention.

An embodiment of the present invention will be described below.
FIG. 1 is a schematic diagram showing an acoustic device according to an embodiment.
The audio device 1 according to this embodiment is a DJ system that integrates two players 2A and 2B that play music and a mixer 3 that controls the players 2A and 2B. Specifically, the audio device 1 functions as an audio playback device and an audio playback control device when operated by a user, and plays music and applies various effects to the music being played.
Effects include those that apply effects such as delay, echo, reverb, or loop to a song to play effect sounds, as well as those that process the original sound before playing it back. Effects that process the original sound before playing it back include those that change the pitch of the original sound before playing it back, such as pitch, and those that filter a specific frequency band of the original sound before playing it back, such as filter.

As shown in FIG. 1, the sound device 1 includes operation units 21A and 21B provided on the players 2A and 2B, respectively, and an operation unit 31 provided on the mixer 3.
The operation unit 21A accepts user operations for the player 2A, and the operation unit 21B accepts user operations for the player 2B. The operation unit 31 also accepts user operations for the mixer 3.

The operation unit 21A includes a jog dial 211A, a tempo slider 212A, a cue button 213A, a play/pause button 214A, a performance pad 215A, a takeover button 216A, a BEAT SYNC button 217A, and a MASTER button 218A.

The jog dial 211A functions as a rotary operator and is a dial used to set the playback direction and playback speed of the music being played on the player 2A.
The tempo slider 212A is a lever that adjusts the playback speed of the music being played on the player 2A. The center of the tempo slider 212A is the playback speed of the original music, and the tempo slider 212A is slid upward in Figure 1 to slow down the playback speed of the music, and downward in Figure 1 to speed up the playback speed of the music.

The cue button 213A is a button that is pressed when a predetermined position in a song is to be set as a cue point.
The play/pause button 214A is a button that is pressed to start or stop the playback of a song on the player 2A.
The performance pad 215A is a general-purpose operator to which various functions relating to playback control can be assigned.

The takeover button 216A is a button that is pressed when changing the range of playback speed that can be changed using the tempo slider 212A. The process of changing the range of playback speed that can be changed using the tempo slider 212A (hereinafter referred to as the setting process for the tempo slider 212A) will be described in detail below. The takeover button 216A may be a dedicated operator, as shown in Figure 1, or may be configured to share the same function as an existing operator.

The BEAT SYNC button 217A is a button that is pressed when executing a BEAT SYNC process that synchronizes the tempos of the music being played on the players 2A and 2B.
The MASTER button 218A is a button that is pressed when setting either the player 2A or 2B as the master deck, or when changing the range of the playback speed that can be changed by the tempo slider 212A.

Similar to the operation unit 21A, the operation unit 21B includes a jog dial 211B, a tempo slider 212B, a cue button 213B, a play/pause button 214B, a performance pad 215B, a takeover button 216B, a beat sync button 217B, and a master button 218B.
When a user operates the operation unit 21A of the player 2A, the audio device 1 plays the music loaded in the player 2A and applies effects to the music being played. The same applies to the player 2B.

In response to user operations, the mixer 3 switches the music playback between the players 2A and 2B, adjusts the volume of each channel, and performs playback with effects applied.
The operation section 31 of the mixer 3 includes effect selection knobs 311A and 311B, effect amount adjustment knobs 312A and 312B, channel faders 313A and 313B, and a crossfader 314.

The effect selection knobs 311A and 311B are used to select an effect to be applied to the music being played on the players 2A and 2B, respectively.
The effect amount adjustment knobs 312A and 312B are used to adjust parameters such as the depth and magnitude of the effect applied to the music being played on the players 2A and 2B, respectively.

The channel faders 313A and 313B are levers used to adjust the output volume levels of the music being played on the players 2A and 2B, respectively.
The crossfader 314 is a lever used to switch the output volume levels of the music output from the players 2A and 2B.
In addition to the above-described components, the operation units 21A, 21B, and 31 may further include a touch panel or the like that detects the position of contact by the user.

FIG. 2 is a block diagram showing a schematic functional configuration of an audio device according to an embodiment.
In addition to the above-mentioned components, the audio device 1 also includes a music data storage unit 4, a control unit 5, and an audio output unit 6, as shown in Figure 2. The functions of the above-mentioned components are realized by a processor operating according to a program in an audio device having, for example, a computer hardware configuration. The functions of the components are further described below.

The song data storage unit 4 is configured to store song data using a hard disk drive (HDD) or flash memory, etc. Song data for multiple songs is stored in the song data storage unit 4 in a predetermined format, such as MP3 format. In addition to audio information, the song data includes tag information such as the song's BPM, artwork, title, artist name, album name, key, number of DJ plays, and genre. Song data stored in the song data storage unit 4 is associated with a timestamp, which is information about the playback position.

The control unit 5 is implemented in the sound device 1 by, for example, a communications interface, a processor such as a CPU (Central Processing Unit), and memory that serves as a working area, and controls the operation of the sound device 1. The control unit 5 includes a setting unit 51, which is realized by the processor operating in accordance with a program stored in the memory or received via the communications interface, a tempo detection unit 52, a first playback unit 53, and a second playback unit 54. The control unit 5 detects user operations on the operation units 21A, 21B, and 31, and supplies information indicating the content of the user operations to each unit within the control unit 5.

When the setting unit 51 receives a user operation relating to the setting process for the tempo slider 212A, it sets the range of change in the playback speed by the tempo slider 212A according to the playback speed of the music at the time of the user operation.
The tempo detection unit 52 detects the tempo of the music being played back on the players 2A and 2B.
The first playback unit 53 plays back music on player 2A and outputs an audio signal to the audio output unit 6. The second playback unit 54 plays back music on player 2B and outputs an audio signal to the audio output unit 6. In addition, the first playback unit 53 applies effects to music being played back on player 2A, and the second playback unit 54 applies effects to music being played back on player 2B.

The audio device 1 may also be configured to include a communication interface, and acquire music data stored in an external storage device, a computer, or the like via the communication interface (not shown), and store the music data in the music data storage unit 4. In this case, the audio device 1 does not include the music data storage unit 4, and the external storage device functions as the music data storage unit 4.
The audio output unit 6 includes an audio output terminal such as a speaker terminal or a headphone terminal, and outputs the audio signals of the music played by the first playback unit 53 and the second playback unit 54 as audio information.

The operation of the control unit 5 during the setting process related to the tempo slider 212A in the sound device 1 described above will be described.
Conventionally, the range of change in playback speed that can be changed by operating the tempo slider has basically been fixed, and in many cases, the tempo range can be set from several predetermined tempo ranges, such as ±6, 10, 16, 100%, etc., by operating the MASTER button 218A, for example.
In such cases, it is possible to set the tempo range for the song being played according to the desired range of BPM change. For example, if the tempo range is set to 100% to allow for large BPM changes, the tempo range must be changed again to make fine adjustments to the tempo.

Also, when using the relative mode, which allows operation based on the relative position of the tempo slider rather than the absolute position, the user needs to keep pressing the SHIFT button with both hands, which makes it impossible to simultaneously perform operations other than tempo adjustment, such as effect operation. Furthermore, if an operation error occurs with the SHIFT button, such as pressing the wrong button, abnormal sound output may occur or the sound output may change suddenly.
In this embodiment, a simple operation using the takeover button 216A of the operation unit 21A or the takeover button 216B of the operation unit 21B allows for easy tempo adjustment.

3A and 3B are enlarged views of the vicinity of the tempo slider 212A in one embodiment. The tempo slider 212A of player 2A will be described below as an example.
3A, a takeover button 216A, a beat sync button 217A, and a master button 218A are provided near the tempo slider 212A. Furthermore, lighting sections 219A and 220A are provided at positions corresponding to the movable ends on both sides of the tempo slider 212A.

When the user slides the tempo slider 212A while a song is being played on the player 2A, the first playback unit 53 changes the playback speed of the song in accordance with the operation. In other words, the tempo of the song being played is adjusted manually.
Meanwhile, when the user turns on the BEAT SYNC button 217A while a song is being played on player 2A, the first playback unit 53 and the second playback unit 54 execute a BEAT SYNC process to synchronize the tempos of the songs being played on players 2A and 2B. In other words, the tempo of the played song is adjusted automatically. Since various well-known techniques can be used for the BEAT SYNC process, a detailed description thereof will be omitted.

After the BEAT SYNC process is executed, a process is generally performed to return the playback speed of the music piece that has been changed by the BEAT SYNC process to the playback speed of the original music piece, or to bring it closer to that of the original music piece.
At this time, when the takeover button 216A is turned on, the setting unit 51 sets the range of change in the playback speed caused by the tempo slider 212A, depending on the playback speed at the time of the user's operation of the takeover button 216A. For example, if the BPM after the BEAT SYNC process is +30% and the takeover button 216A is turned on at this point, the setting unit 51 sets the range of change in the playback speed caused by the tempo slider 212A from −30% (upper movable end) to +30% (lower movable end).
In other words, after executing the BEAT SYNC process, the user can simply turn on the takeover button 216A to change the range of playback speed change caused by the tempo slider 212A to a suitable range that corresponds to the current playback speed, making it easy to fine-tune the tempo.

As described above, the range of change in playback speed caused by the tempo slider 212A may be set according to the ratio (ratio of BPM values) between the playback speed of the original song of the song being played and the playback speed when the takeover button 216A is turned on, or may be set according to the difference (difference in BPM values) between the playback speed of the original song of the song being played and the playback speed when the takeover button 216A is turned on. Also, the ratio and difference in BPM values may be set in combination, or the method for setting the range of change in playback speed caused by the tempo slider may be switched according to user specifications or various conditions.
Furthermore, the range of change in playback speed by the tempo slider 212A may be set according to the difference in playback speed between the songs being played by players 2A and 2B. For example, if the difference in playback speed between the songs being played by players 2A and 2B is small, more precise adjustment can be made by setting the range of change in playback speed by the tempo slider 212A according to the difference in playback speed.

As explained above, if the range of change in playback speed by the tempo slider 212A is set in response to user operation of the takeover button 216A, the operating position of the tempo slider 212A may not match the playback speed of the music being played. If the tempo slider 212A is operated in such a state, there is a problem that abnormal sound output may occur or the sound output may change suddenly.
Therefore, when the takeover button 216A is turned on, the control unit 5 temporarily disables operation of the tempo slider 212A and performs processing to prompt the user to match the operation position of the tempo slider 212A with the playback speed of the music being played. Here, "disabling" means that the tempo slider 212A can be physically operated, but the playback speed will not be changed based on the operation of the tempo slider 212A.

Specifically, the control unit 5 lights up the lighting section 219A corresponding to the upper movable end if the playback speed when the takeover button 216A is turned on is slower than the playback speed of the original song, and lights up the lighting section 220A corresponding to the lower movable end if the playback speed is faster than the playback speed of the original song. The example of Fig. 3B shows an example in which the lighting section 220A corresponding to the lower movable end of the tempo slider 212A is lit up if the playback speed when the takeover button 216A is turned on is faster than the playback speed of the original song.
Next, the control unit 5 determines whether the tempo slider 212A has been slid to the movable end that lights up the lighting unit 219A or 220A, and if it determines that the tempo slider 212A has been operated, it validates the operation of the tempo slider 212A within the range of change set by the setting unit 51. Here, "validating" means that the tempo slider 212A can be physically operated and that the playback speed is changed based on the operation of the tempo slider 212A.
In other words, after turning on takeover button 216A, the user can change the range of the playback speed controlled by tempo slider 212A to a suitable range that corresponds to the current playback speed, and can also match the operating position of tempo slider 212A with the playback speed of the music being played, simply by sliding tempo slider 212A against the movable end where lighting section 219A or 220A is lit. Since the sliding operation of pressing tempo slider 212A against the movable end in this way does not require delicacy, the burden on the user is small and the possibility of operating it incorrectly is low.

As described above, after the BEAT SYNC process is executed, when the user turns on the takeover button 216A, the range of change in playback speed caused by the tempo slider 212A is changed to a suitable range corresponding to the current playback speed, and when the user slides the tempo slider 212A to the limit where the lighting section 219A or 220A is lit, the position of the tempo slider 212A matches the playback speed of the music being played. In other words, by simply turning on the takeover button 216 and sliding the tempo slider 212A to the limit, the user can change the range of change in playback speed caused by the tempo slider 212A to a suitable range corresponding to the current playback speed and match the position of the tempo slider 212A with the playback speed of the music being played. This allows the user to easily operate the tempo slider with one hand or both hands, and can simultaneously perform operations other than tempo adjustment, such as effect operation.
Furthermore, by temporarily disabling operation of the tempo slider 212A until the operation position of the tempo slider 212A matches the playback speed of the music being played, problems such as abnormal sound output or sudden changes in sound output can be prevented. Furthermore, by matching the operation position of the tempo slider with the playback speed of the music being played, the state of the tempo adjustment can be grasped intuitively and instantly.

In the above example, a series of processes is performed when the takeover button 216A, which indicates a user operation to change the range of change in playback speed using the tempo slider 212A, is turned on after the BEAT SYNC process (mode) for synchronizing the tempos of at least two songs is set, but the present invention is not limited to this example.
For example, when the BEAT SYNC button 217A, which sets the BEAT SYNC process (mode), is turned on, a series of processes may be executed without waiting for the takeover button 216A to be turned on. For example, the above-mentioned change range may be set according to the playback speed of player A when the BEAT SYNC process (mode) is completed. In this way, when the BEAT SYNC button 217A is turned on, the change range of the playback speed using the tempo slider 212A is set according to the playback speed after the BEAT SYNC button 217A is turned on. This further reduces the amount of user operation, making it possible to meet the needs of beginner users and users who wish to simultaneously perform operations other than tempo adjustment, such as effect operation. Note that it may be possible to select whether the trigger is only the ON operation of the BEAT SYNC button 217A that sets the BEAT SYNC processing (mode) or the trigger is only the ON operation of the takeover button 216A after the BEAT SYNC processing (mode) is set, or it may be possible to execute only one of them. When the trigger is only the ON operation of the BEAT SYNC button 217A, for example, the present invention can also be similarly applied to a configuration that does not include the takeover button 216A described in this embodiment.

Next, a method for controlling an audio device according to an embodiment of the present invention will be described with reference to the flowchart of FIG.
4 shows a flowchart of the setting process for the tempo slider 212A. The following describes, as an example, the setting process for the tempo slider 212A while a song is being played on the player 2A.
First, when the BEAT SYNC button 217A is turned on (YES in step S101), the first playback unit 53 and the second playback unit 54 execute a BEAT SYNC process to synchronize the tempos of the songs being played back by the players 2A and 2B (step S102).
Next, when the takeover button 216A is turned on (step S103 YES), the control unit 5 disables operation of the tempo slider 212A (step S104), sets the range of change in the playback speed caused by the tempo slider 212A depending on the playback speed when the takeover button 216A is turned on (step S105), and lights up the lighting unit 219A or the lighting unit 220A depending on the playback speed when the takeover button 216A is turned on and the playback speed of the original song (step S106). Note that the processes of steps S104 to S106 may be performed simultaneously, or may be performed in a reverse order.

The control unit 5 determines whether the tempo slider 212A has been slid to the movable end that illuminates the lighting portion 219A or 220A, and if it determines that the tempo slider 212A has been operated (YES in step S107), the control unit 5 validates the operation of the tempo slider 212A (step S108) and turns off the lighting portion 219A or 220A that was lit in step S106 (step S109). Note that the processes of steps S108 and S109 may be executed simultaneously, or may be executed in reverse order.
As described above, if only the ON operation of the BEAT SYNC button 217A is used as a trigger, the determination of the ON operation of the takeover button 216A described in step S103 may be skipped.

In Figures 3 and 4, the tempo slider 212A for player 2A has been used as an example for explanation, but similar processing is performed for the tempo slider 212B for player 2B. That is, a takeover button 216B is provided near the tempo slider 212B, as well as a BEAT SYNC button 217B and a MASTER button 218B. Furthermore, lighting sections 219B and 220B are provided at positions corresponding to the movable ends on both sides of the tempo slider 212B (see Figure 1).

When the takeover button 216B is turned on after the BEAT SYNC process is executed, the setting unit 51 sets the range of change in the playback speed by the tempo slider 212B according to the playback speed when the takeover button 216B is turned on. Then, the control unit 5 temporarily disables operation of the tempo slider 212B, and lights up the lighting unit 219B if the playback speed when the takeover button 216B is turned on is slower than the playback speed of the original song, and lights up the lighting unit 220B if the playback speed is faster than the playback speed of the original song.
Furthermore, the control unit 5 determines whether the tempo slider 212B has been slid to the movable end that lights up the lighting unit 219B or 220B, and if it determines that the tempo slider 212B has been operated, it enables operation of the tempo slider 212B within the range of change set by the setting unit 51.

According to one embodiment of the present invention as described above, in an audio device equipped with a tempo slider for changing the playback speed of a song being played, when a user operation to change the range of playback speed that can be changed by the tempo slider is received, the range of playback speed that can be changed by the tempo slider is set according to the playback speed at the time of the user operation. This allows for intuitive operation and realizes highly user-friendly tempo adjustment.
Furthermore, according to one embodiment of the present invention, the range of change in playback speed caused by the tempo slider is set according to the difference between the playback speed of the original song being played and the playback speed at the time of user operation. This makes it possible to easily set a suitable change range according to the relationship between the playback speed of the original song and the current playback speed.
Furthermore, according to one embodiment of the present invention, the range of change in playback speed caused by the tempo slider is set according to the ratio between the playback speed of the original song of the song being played and the playback speed at the time of user operation. This makes it possible to easily set a suitable change range according to the relationship between the playback speed of the original song and the current playback speed.

Furthermore, according to one embodiment of the present invention, when a user operation to change the range of playback speed change caused by the tempo slider is received after a mode for synchronizing the tempos of at least two songs is set, the range of playback speed change caused by the tempo slider is set according to the playback speed at the time of the user operation to change the range of change. Therefore, after setting the BEAT SYNC process to synchronize the tempos of songs being played on players 2A and 2B, the range of playback speed change caused by the tempo slider can be suitably set at the user's desired timing.
Furthermore, according to one embodiment of the present invention, when a user operation to set a mode for synchronizing the tempos of at least two songs is accepted, a change range is set according to the playback speed after the user operation to set the mode. Therefore, when setting BEAT SYNC processing to synchronize the tempos of songs being played on players 2A and 2B, an appropriate change range of the playback speed can be automatically set using the tempo slider, thereby reducing the amount of user operation required.

Note that the audio device with the above-described functions is not limited to the examples described in the above embodiments, but may also be, for example, a mixer or a DJ controller with a mixer function. The present invention may also be applied to computers, smartphones, and tablet devices that run DJ applications. In such cases, the same effects can be achieved even with audio devices that do not have a tempo slider component.
Furthermore, the present invention may be applied not only to DJ equipment and DJ applications, but also to music applications, streaming services using the Internet, etc. In such cases, the present invention can be applied to automatic playback using a playlist, for example.
Furthermore, while the above embodiments have described a two-channel audio device having two players 2A and 2B, similar functions can also be realized in, for example, a four-channel audio device. Furthermore, the present invention is not limited to DJ equipment, but can also be applied to audio devices such as general mixers and electronic musical instruments, as well as DAWs (Digital Audio Workstations) and DTMs (Desktop Music Players).

The above describes in detail preferred embodiments of the present invention with reference to the accompanying drawings, but the present invention is not limited to such examples. It is clear that a person with ordinary skill in the technical field to which the present invention pertains could conceive of various modified or altered examples within the scope of the technical ideas set forth in the claims, and it is understood that these naturally fall within the technical scope of the present invention.

1...sound device, 2A, 2B...player, 3...mixer, 4...music data storage section, 5...control section, 6...audio output section, 21A, 21B, 31...operation section, 51...setting section, 52...tempo detection section, 53...first playback section, 54...second playback section, 211A, 211B...jog dial, 212A, 212B...tempo slider, 213A, 213B...cue button, 214A, 214B...play/pause button, 215A, 215B...performance pad, 216A, 216B...takeover button, 217A, 217B...BEAT SYNC button, 218A, 218B...MASTER button, 311A, 311B...effect selection knob, 312A, 312B...effect amount adjustment knob, 313A, 313B...channel fader, 314...cross fader.

Claims (5)

An audio device having a tempo slider for changing the playback speed of a song being played,
an operation unit that accepts a user operation to change a range of the playback speed that can be changed by the tempo slider;
an audio device comprising: a setting unit that, when the operation unit receives the user operation, sets the range of change of the playback speed caused by the tempo slider according to the difference between the playback speed of the original song of the song being played and the playback speed at the time of the user operation, or according to the ratio between the playback speed of the original song of the song being played and the playback speed at the time of the user operation. the operation unit further receives a user operation for setting a mode for synchronizing the tempos of at least two pieces of music;
2. The audio device according to claim 1, wherein when the setting unit receives the user operation to change the range of change after setting the mode, the setting unit sets the range of change of the playback speed caused by the tempo slider according to the playback speed at the time of the user operation to change the range of change. the operation unit accepts the user operation for setting a mode for synchronizing the tempos of at least two pieces of music;
2. The audio device according to claim 1, wherein, when the setting unit receives the user operation to set the mode, the setting unit sets the range of change of the playback speed caused by the tempo slider in accordance with the playback speed after the user operation to set the mode. A method for controlling an audio device equipped with a tempo slider for changing the playback speed of a song being played, comprising:
receiving a user operation to change a range of the playback speed that can be changed by the tempo slider;
and when the user operation is accepted, setting the range of change of the playback speed by the tempo slider according to a difference between the playback speed of the original song of the song being played and the playback speed at the time of the user operation, or according to a ratio between the playback speed of the original song of the song being played and the playback speed at the time of the user operation. A program for causing a computer to function as an audio device having a tempo slider for changing the playback speed of a song being played,
an operation unit that accepts a user operation to change a range of the playback speed that can be changed by the tempo slider;
a setting unit that, when the operation unit receives the user operation, sets the range of change in the playback speed caused by the tempo slider according to the difference between the playback speed of the original song of the song being played and the playback speed at the time of the user operation, or the ratio between the playback speed of the original song of the song being played and the playback speed at the time of the user operation .