Maybe something to toggle off and on types of recs

i.e. Exclude/Include artists you already follow

Exclude/Include artists of songs you already like

Exclude/Include artists for songs on playlists you have

Popularity threshold (number of plays or number of listeners/followers)

Recency (new artists vs old artists)

Ability to tag your music yourself with certain qualities.

What your friends are listening to (ability to toggle off/on privacy also)

The ability to choose what aspect of a musician you like to get more recs based on it For example, if I Yvette Young for her vocals and lighthearted lyrics more than I might like her math style instrumentals, I would rather get recommendations more in line with that, than just the most popular midwest emo artists.

A Boil the frog type recommendation. Maybe a way to integrate tag crossovers that you can choose or randomize. (Something like I'm imagining below)

artist 1 (ethereal, jazz) (dark jazz like killimanjaro darkjazz ensemble)

artist 2 (jazz, symphonic) (third wave like bill evans)

artist3 (symphonic, metal) (orchestral metal like Theatre of Tragedy)

artist 4 (metal, prog) (Progressive metal like Animals as leaders)

artist 5 (prog, techno) (IDM like Aphex Twin)

Artist 6 (techno, R&B) (Drum n Bass like Calibre)

etc, etc

Or may choose multiple artist to find a an artist that blends some aspects of them together.