I like it, but it's not perfect. It's not a failure by any means but it could use improvements.

I think it should have its own "macro" system or I guess a music maker interface but something more user-friendly than typing codes, although that can be an alternative for people who prefer that and also having a way to share and copy-paste music.
It should have things like setting delays between each note and also the duration of holding a note but that is something only possible on instruments like a violin or flute and not a harp.

It could use its own hotbar mode like people have been suggesting.