I have ITunes Match...... I matched my songs.....deleted them on my Mac....then downloaded them from the cloud. It works great on Itunes and the file format says "Matched AAC Audio File" Though, if I drag a song from Itunes and put it on my desktop, it's saved as a m4a. Why? This has become a problem because my Ipod Nano 2nd wont allow me to upload the m4a. I tried changing the extention to .aac but even though I was able to upload to the Nano, the Nano restarts when it tries to play the song. I know I could convert the m4a to mp3 but the idea with Itunes Match was to get a real good aac version. I'd rather not convert to an inferior file type.