have you looked into
https://fedi.directory/tag/music/
also,
look at public timelines ('Live feeds' > 'This server') of instances dedicated to music:
Luka Prin/ce Lucija (@luka@sonomu.club)
some music-focused communities (always check their rules and moderation practices!): https://ravenation.club https://musicians.today https://musician.social https://social.bitwig.community https://linernotes.club https://stereodon.social https://metalhead.club https://soc.gsg.live https://musicworld.social https://jazztodon.com https://438punk.house https://skastodon.com https://djs.social ~ https://mastodon.art https://sunny.garden https://indiepocalypse.social
SoNoMu (sonomu.club)
also, ours:
https://sonomu.club/public/local