All iTunes tracks are 128kbps but are encoded using AAC (MPEG4), which they claim is a small file size but far superior sound quality to a 128kps MP3.
Of course not everyone agrees that the sound quality is better!!
iTunes blurb:
"When you import a song into the library, the song is encoded and stored on your hard disk. The amount of space the file takes up depends on the song and the import settings you choose in iTunes Preferences. The import settings also affect the audio quality of the imported song. Larger files take up more hard disk space, but generally sound better.
If you have a Macintosh computer with QuickTime 6.2 or later installed, or a Windows computer, the default encoding format is MPEG-4 AAC, a compressed format that rivals the sound quality of audio CDs. If you have an earlier version of QuickTime on your Mac, the default format is MP3, or whatever you last chose in the Advanced pane of iTunes Preferences (in the Importing section). You can play AAC files using iTunes and other applications that support QuickTime, and on your iPod. You can play MP3 files on your computer or most digital music players.
AAC-encoded files sound as good as or better than MP3 files encoded at the same or even a higher bit rate. For example, a 128 Kbps AAC file should sound as good as or better than a 160 Kbps MP3 file. Because the bit rate is lower, the AAC file will also be smaller than the MP3 file. AAC files allow you to store the most music on your hard disk or iPod. The High Quality AAC setting creates files that are usually less than 1 MB for each minute of music. The High Quality MP3 setting creates files that are about 1 MB in size for each minute of music.
The AIFF and WAV encoders do not compress the songs. AIFF and WAV are very high quality files that are several times larger than AAC or MP3 files and take up a large amount of hard disk space (about 650 MB per CD or 10 MB per minute of music). Songs imported using the Apple Lossless encoder offer the same quality as AIFF or WAV, but they take up about half the size (about 5 MB per minute of music). Files encoded using the Lossless encoder can be played in iTunes, applications that support QuickTime, and iPod models that come with a Dock connector.
If you plan to burn high-quality audio CDs with the songs you're importing, you should use the Apple Lossless or AIFF encoder for the best results. (The Apple Lossless encoder uses the least room on your hard disk, but AIFF files can be played in more applications.) The WAV encoder is primarily for use with Windows computers that are not using iTunes, or computers that do not have MP3 software. You can fit the same number of songs on an audio CD whether you use Apple's Lossless, AIFF, or WAV format when you import the songs into iTunes, but the songs will take up less space on your hard disk if you use the Apple Lossless encoder. "
I am sure I read somehwere that when you download from iTunes you have the option of doing so as a high quality MP3. Maybe that's the US version...
Edited to add: I've checked with iTunes and downloads are 128kbps AAC and nothing else currently. Later this year as iPods get bigger you will be able to get downloads in Apples "lossless" format which is apparently as good as a WAV but much smaller in size.
at having spent money on tracks that are no use to me at all.
