DBpowerAMP Music converter supports practically every audio type created: mp3, mp4, m4a, wma, Ogg Vorbis, AAC,... It converts audio formats whilst preserving ID Tags, so you will not have to reedit them, though you can edit them if you want.
DdBpowerAMP helps you when doing your music tasks, it shows you how to convert your audio files. It converts the formats very fast and you will have them perfectly converted in just a while.
In addition, it integrates itself in your Internet Explorer, so you will only have to right click on a file to convert it into other format.
30 days trial version