I've heard of them both. I used Piskel for awhile and am currently using Asprite for pixel art. Although most of the time I just use the crappy pixel editor in Game Maker for small things.
Music is something I really need to dive into. I used to pay an ex-student to make my music but he is really busy now. I am okay at music theory so I think it wouldn't be too hard for me. It is just finding the time. I seem to find less and less everyday :/