This applet will create new Music track playlists based on each selected entry of a specified tag. That is, create individual playlists for each Artist, Album Artist, Album, Composer (and their "Sort" siblings), Genre, or Year.
For OS X 10.6 or later.
A good companion to this applet is Merge-Delete Playlists.
A new playlist will be created for each checkmarked entry and will contain Music tracks--in this case--whose artist tag is the same as the entry. The red-colored entries are already playlists.