You have entered into a glorious pool of sound. You are traveling through time with a weightless companion known as music, and as Liquid Parallax as your tour guide, prepare to be exhilarated.
There has yet to be a satisfactory system or program that allows tagging multiple custom keywords for a music collection that works on a personal audio library. Besides documenting the available options, this is sort of a request to developers (especially on mac or multi-OS) who use digital music (and possibly iTunes). Let’s get open...
iTunes Tagging like Last.fm Multi-Genre