Consonance is a lightweight GTK+ music manager that aims to be fast, bloat-free, and light on memory consumption.
It is written completely in C and GTK+. Some of the features are:

* Library management using sqlite3
* Multiple views
* OSD support
* Tag Editing
* mp3, ogg, flac, modplug, wav and Audio CD support
* Last.fm submission
* Playlist management (M3U)
* DBUS management interface