Helium

A feature-rich but easy-to-use audio manager that provides a collection of tools for playing songs, tagging and syncing with portable devices.

With Helium Music Manager, you can catalog, search, categorize, sort, edit and even play your music media or audio files. You can add various information to each track, insert a picture (cover art), etc.
Supported content includes MPEG and MPEG+, MP4, FLAC, WAVE, OGG, WMA, AAC, APE, WavPack, AIFF.