how do i use m4a files?

hi im new to xbox came from the ps3 world lol. anyway i was wondering how can i play m4a files? i have a drive filled with them and the 360 doesnt even see it.

ok thanks!

Not compatible.MonsieurX

Are you sure?

I think it's compatible from what I searched online; you just need to download the AAC decoder. Note the music files must be DRM-free to work.

Download from Xbox Marketplace (online):

http://marketplace.xbox.com/en-US/Product/Optional-Media-Update/66acd000-77fe-1000-9115-d802fffe07df

It's available through the Dashboard too, just not sure where ..