I started the Original Music community, but its mostly been me using it. If you want to contribute, maybe we can get some more to join there! there is also Hivesicians, World of Music, Alien Art Hive (not specifically music, they have some qualifications for posting there, but definitely could be music, depending on what you make), and just 'Music'.

there are others but they don't seem to be particularly active, or at least not curated much.