if your music was recently purchased, iTunes will happily convert the file to MP3.

Now when you right-click on a music track, there is an option to Create MP3 Version or Convert Selection to MP3. Your goal is to change the Import Using from the default setting to 'MP3 Encoder'. In older versions of iTunes, click on Edit / Preferences / Importing (or Edit / Preferences / Advanced / Importing). In iTunes 8 or later versions, go to Edit / Preferences / General and click the Import Settings button. You'll need to change your import settings to get iTunes to import the track as MP3. Probably it says 'Create AAC Version' or 'Convert Selection to AAC', which is useless because your iTunes tracks are already in AAC format! If you right-click on a music track in iTunes, there is an option to Convert Selection or Create Version in some other format. Hence, the need to convert iTunes music to the MP3 format. Understandably, this makes owners of non-iPod music players (as well as Linux users) a little upset. You CAN copy them to your portable music player, as long as you bought that player from Apple and it says iPod on it. iTunes music tracks are proprietary and cannot be played on a computer which does not have the iTunes software. But Apple's iTunes software doesn't give you MP3 files when you buy a song. You can burn MP3s to a CD and they'll play just fine on almost any modern CD player. An MP3 music track can be played on almost ANY player, whether it's portable or computer-based. But DRM often restricts the consumer from doing perfectly valid and reasonable things with music they own, like making a backup copy, burning a CD, or converting to another audio format. DRM (Digital Rights Management) was created by the entertainment industry so they could control the duplication and dissemination of their content. Prior to April 2009, the iTunes tracks that you purchased were in a 'DRM protected' AAC audio format.

MP3 has been an open standard for many years, but it's not always simple to convert iTunes music tracks to MP3 format.

you paid for those songs and now you can't play them outside of the iTunes environment, on hardware not supported by Apple, or on operating systems not supported by iTunes.

Convert itunes to mp3 free on line