Hi ​@Nightshifter !

HiFi is automatically included in Deezer Premium, Deezer Duo and Deezer Family subscriptions.
Now it's up to you to choose a playlist or an album according to your musical taste that you want to listen to .

see attached below

Hi ​@Nina Nebo

I have enrolled in Premium plan but randomly coming across with HIFI songs wasn't in my expectations. I wish I could find a massive Hifi collection of songs. 

Here in the link below are Hi Fi playlists, so I hope you will find something for yourself.
You can also start creating your own Hi Fi playlist with songs that meet your expectations .

https://www.deezer.com/search/hi%20fi/playlist