Nice, the main game idea is actually pretty solid, the music works pretty well, and the pixel art for the characters is nice. I'd suggest making all the art assets at the same pixel art resolution, as it's pretty jarring seeing different ones next to each other. There's not a lot of "music" in the gameplay though - just making the bullets look like music notes and calling it "Musical Weapons" seems a little tenuous. :)
But my main problem with it is just how easy it plays. It could be a fun little Gauntlet-alike if it was a lot harder, but it's too easy to just plod through the levels and feel in no real danger from the enemies.