Changing the Key of a Pre-recorded Song in GarageBand

Hello-

I have been told in another forum that it is possible to take a pre-recorded song ripped from a CD and use GarageBand to change the song's key. I cannot find information on this on the Apple site or in GarageBand. Can someone let me know if this is possible and, if it is, can it be described in a few steps? Thanks.

In Garageband click on the arrows on the transport bar until it shows the key, then click on the key and select whichever you want.