Mp3tag is a powerful and yet easy-to-use tool to edit metadata of common audio formats where it supports ID3v1, ID3v2.3, ID3v2.4, iTunes MP4, WMA, Vorbis Comments and APE Tags.
via Mp3tag – the universal Tag Editor ID3v2, MP4, OGG, FLAC, ….
Note: Don’t use ID3v2.4 as is causes issues with Windows Media Player and possible other players.