In playlists, all songs have a number on the left side.
If would be very convenient if we could edit that number.
Let's say if want to move a song in the middle of a playlist to the top, I could just change that number (type "1" to place it at the top of the list for example).
I don't how difficult it would be to implement this (adding an input box next to each song), but that would make it much easier to edit a set list within a playlist.