I moved from Lemmy.ml because I liked the name of Lemmy.world and it ran a newer Lemmy version which meant I could make communities.
I moved from Lemmy.world because they defederated from piracy communities they didn't even host (but for some reason still kept the small piracy community they DID host)
From thelemmy.club because I couldn't see the Hackintosh community from there (probably defederated)
Now I spent some time looking on join-lemmy.org and checked out some instances and this (lemy.lol) instance seemed good, so I chose that.
When I analyze a melody I play on a piano, I see that it reflects the music I heard that day or sometimes, even music I heard and liked years ago.
Having parts similar or a part that is (coincidentally) identical to a part from another song is not stealing and does not infringe upon any law.