Practice files in mp3 format have been posted for movements 1, 4, 7, 11, and 12 of the Bach Magnificat. You can play them directly from the website, or download them to your own computer — on most systems, you can do this by right-clicking on the link (i.e., “Sop 1”) and choosing “Save link as.”
These files will play automatically in audio programs such as Windows Media, Quicktime, Itunes, etc., and can be easily copied onto a music player such as an iPod.