Some more resources

https://www.scenemusic.net/demovibes/ (streaming radio)

http://jsspeccy.zxdemo.org/jsmodplayer/ (mod player in javascript)

http://modarchive.org/ (tens of thousands of mods and similar formats)

ftp://ftp.funet.fi/pub/amiga/audio/ (the venerable funet.fi audio and mod archive)