Hi HN! I frequently organize my playlists as my song collection changes. For example, I have a playlist for my recent songs, a playlist for my current favorites, a playlist for just Japanese songs etc.

I was getting lazy to do it so I hacked around over a few weekends and made this mainly to scratch my itch :)

Songbird lets you add smart playlists that automatically update itself according to your song collection / listening behavior.

Work is very much still in progress, feedback welcome!