Well done! I think I'll use this. A few suggestions:

- You should add custom page titles for each album, search result, etc. It's hard to figure out what's what in the Back menu in my browser because they're all the same.

- Would be nice to have a way to drag multiple songs, or an entire album into a playlist.

- When dragging, droppable zones (playlists) should highlight, and when hovering over them the highlight should get even stronger so I know it's ready to be dropped.

- History doesn't seem to work.