There is !imadethis@lemmy.zip
People do post their music there sometimes.
A community for people playing music, alone, or with others.
I can’t remember how to link to a community but there’s a few on different instances under the name “musicproduction” where you’re invited to share your creations.
Edit: e.g. !musicproduction@lemmy.ml
thanks!
I mean, you could do it right here I suppose?