Oh, my word. I have... quite a few. Mostly for establishing characters, their concepts and their backstories rather than "theme tunes" or anything like that. Here are a few:

Songs for Sorcha (my horrible thinblood Dunsirn): https://open.spotify.com/playlist/7tF9xRKerX7SIgbuGNV8L1?si=_Fm3rLUQS7Wp7mZLAB2JAQ

Related: a soundtrack for her disastrous relationship with a nomadic Salubri who's so far up the power ladder from her he's basically on the roof:https://open.spotify.com/playlist/6BMSAF2LcKj6BJZUOOAmhM?si=BpkOx6Q-Rci6FLtqhUg6Sg

Hezekiah, my Minister of Set and potential LARP character if I ever do a LARP: https://open.spotify.com/playlist/7ie7ljmBwJD5GN5jckAiQr?si=gyVOU8rQQkCgrUmAw7iQEA

Lamorne tunes, because a fifth century Celtic warlord turned Knight of the Round Table turned underworld pain goddess deserves at least a few bops: https://open.spotify.com/playlist/5OMsboQI8r4HAvmiVJ7OM2?si=-urAtatrRZG9TjTlcBA7jA