When you purchase music from iTunes Store, you actually get DRM protected content (in protected AAC or M4P format), which you will not be able to play on MP3/MP4 players and other non-Apple mobile players. You cannot directly transfer the M4P files to Zune, PSP, BlackBerry, either. In such case, the option is to burn those tracks to an audio CD and then rip them once again to your computer hard drive wherein the DRM will be removed and you will get the tracks in (DRM free) MP3 format. After this you will be able to transfer them to Zune, PSP, BlackBerry.
In case you have purchased a great amount of music from iTunes Store, you can go ahead and use TuneClone M4P to MP3 Converter which acts as a Virtual CD-ROM drive on your PC and lets you remove the DRM element without having to waste actual CD's, with the music ID3 tags info well preserved. Below is the detailed steps:
Step 1. Create a new playlist in iTunes and add the M4P songs to the playlist.
Step 2. Download and install TuneClone M4P to MP3 Converter. Run it. In the main interface, click the "Settings" button. In the pop up window, you can choose the output folder, output file name format, output format (choose MP3 here), etc for the output files.
Step 3. Back to iTunes. Click the "Burn Disc" button. In the pop-up window of "Burn Settings", select "TuneClon Virtual_CD-RW" from the "CD Burner" drop-down list, click the radio button next to "Audio CD" and tick "Include CD Text" option. Click "Burn" to start burning. Note: You can check whether TuneClone virtual CD drive is successfully installed and where it is installed in the bottom left corner of the TuneClone interface.
Step 4. Upon the completion of burning the disc and encoding the music, you can open the TuneClone manager screen to show all the converted music files. To locate the output folder, simply click the "Folder" tab on the interface.
P.S. Burn and Rip iTunes M4P to MP3 for Zune PSP BlackBerry
1. Insert a CD-R or CD-RW disc into your CD-ROM drive.
2. Burn the iTunes M4P playlist to make an audio CD. You cannot select the "MP3 CD" option since it requires the DRM protected iTunes M4P files be converted to MP3 or WMA files for Zune, PSP, BlackBerry.
3. After the audio CD is successfully burned, insert the disc into your CD-ROM drive again. Then you can use iTunes or Windows Media Player to import the music tracks on the burned disc as MP3 or WMA files.