Qt is a good choice. I would also consider SDL or Raylib if you don't mind having to code your own UI. It is not that difficult in practice, most music softwar

Qt is a good choice. I would also consider SDL or Raylib if you don't mind having to code your own UI. It is not that difficult in practice, most music software have their own custom built UI and that gives them a lot more personality than generic stuff, IMO.