Glad my stream helped!
Custom music is not currently an option, sadly.
It was mentioned that it may/will be added at a later date.
For the now the options for music are using the in-game tracks, which are beautiful, or..
If you are GMing a campaign for friends, you could use one of those shared-room youtube websites.
You can create playlists for towns, combat, and ambiance and then just play them as needed.
A little hacky but it'll work.
