I can't publish it, even though I created my own music

I attempted to make my own music last night, but I decided to name it "The Afterlife, Symphony #4," this was suppose to have 4 movements, but every time when I save it earlier, it wouldn't let me save and I have no choice but to name it "Hi" for temporary and since I've finished my music a few hours ago, I tried to publish it but I couldn't publish, in my head I'm thinking that it has copyrighted music, but I legit made my own music.