Difference between AAC and m4a files, converting from AAC to useable format

AAC is the name of the MPEG-2 compression format usually used by iTunes, .m4a is the corresponding file extension iTunes is using (and expecting). So basically there is no "difference" between AAC and m4a files.

If you have music files with the extension .aac, just try renaming them to .m4a and see if iTunes can play them thus.

Alexander.

iTunes uses AAC data wrapped in an MPEG 4 container file. If you got some *.AAC files, and they're just raw AAC files, then you need to wrap them in an MPEG 4 container. The only way I know to do this is using the foobar 2000 program. You can find more information at http://www.hydrogenaudio.org and http://www.foobar2000.org