Ex Falso / Quod Libet - A Music Library/Editor/Player
Quod Libet is a music management program. It provides several different ways to view your audio library, as well as support for Internet radio and audio feeds. It has extremely flexible metadata tag editing and searching capabilities.
Ex Falso is a tag editor with the same tag editing interface as Quod Libet.
For information on how to build/install/test Quod Libet check out