I found Cosine Club recently and it's pretty cool. They have a model which just finds the top ~50 most similar tracks to the one you're searching for. They use a model trained from this paper [0] which was trained based on four types of similarity: 1) two samples from the same song, 2) two samples from the same album, 3) two samples from the same artist, 4) two samples from the same record label.

I get pretty good recommendations, and they're different from Spotify which is nice.

[0] https://repositori.upf.edu/bitstream/handle/10230/54158/Alon...