The title derives its name from the notion that if the grey-haired doorman whistles your tune, then it's a hit.
The series was accused of being slow to catch on to the popularity of punk acts. Host Bob Harris was even physically attacked by Sid Vicious in March 1977 because of his perceived antipathy towards the genre. Harris admits that he became "the symbol of everything they hated". In 1978, Anne Nightingale took over from him because she was regarded as more receptive to the new music.
16 episodes are missing from the archives, and 54 are incomplete.
The series was commissioned by David Attenborough during his time as a BBC executive, although Attenborough has admitted that he never actually watched it as he doesn't like rock music.
The series' emphasis was on albums. Artists were not stopped from performing singles but according to Michael Appleton they had to be from albums.