[munificent]

I think a more fundamental problem is that people like music for very different reasons. Even the same person may define "similar" very differently at different points in time.

If I want music "like" "Groove is in the Heart", is it because:

* I want mid-tempo house-like dance music

* I want major key songs with female singing

* I want songs with rap interludes

* I want 90s music

* I want fun party music

* I want music that reminds of that awesome trip I took with my friends a few years ago where we played a bunch of songs over and over

There is no right answer to this question. But, outside of just looking for playlists, no music app I've seen gives you a way to specify in what way recommended music should similar to the current song.

I see this effect most acutely when I listen to something that happens to be popular. For many people "heard it a lot when doing this fun social thing" is one of the main reasons they like a particular song. This was true for me too when I was younger. But for me today, I'm mostly oblivious to popularity. I just like stuff that sounds a certain way.

Whenever I stumble onto a song that has a particular sound I like that happens to be well-known, the recommendation algorithm just starts throwing other popular stuff at me that sounds totally different.

[belthesar]

Ironically, this is something that I think Pandora solved quite well with their recommendation engine. By virtue of creating a station around a particular vibe, even if 5 playlists all started with the same seed song, weighting other songs up and down on each station would curate a different listening experience, by virtue of finding how those are similar. Where Pandora was limited (at least, the last time I used the service) was the pre-seeding process is a bit arduous and opaque. I'm not sure how you make that easy to interact with, as going a layer beneath to the "why" a song was recommended and allowing folks to influence the graph at that layer sounds like a daunting UX challenge.

[lowbloodsugar]

See, "Groove is in the Heart" makes me think of "Calling all units to broccolino" by Calibro 35. So I might add:

* Musicians having fun with instruments.