When you open GarageBand 2 songs in Logic Pro 7.1 or Logic Express 7.1, there are some differences in how Follow Tempo will work with audio tracks, depending on whether the song was created in GarageBand 2.0 or 2.01.
Audio recorded directly in Logic 7.1 can follow subsequent tempo changes or changes to the Project Key (initial key signature). Likewise, audio recorded in GarageBand 2.0 or later can also follow tempo and key transpositions when the song is opened in Logic 7.1. However, there are a couple of important differences in how this is achieved.
Songs created in GarageBand 2.0
When you open a GarageBand 2.0 song in Logic 7.1 and enable the Follow Tempo feature in the Region parameter box, this allows the audio files to follow tempo changes in Logic, but it doesn't allow them to follow the project key. If you want to transpose audio that was originally recorded in GarageBand 2.0, use the Transpose parameter that appears in the Region Parameter box after you enable Follow Tempo.
Set the Transpose value to whatever number of semitones is necessary for the audio to play in the same key as the Logic song. In the picture above, we transposed our audio up two semitones to change the key from C to D.
Songs created in GarageBand 2.01 or later
When you open a GarageBand 2.01 or later song in Logic 7.1 and enable the Follow Tempo feature, this allows the audio file to follow tempo changes and the project key in Logic. To make audio recorded in GarageBand 2.01 play in the same key as the Logic project (no matter what key it was originally recorded in), just set the initial key signature in the Signature track to the same one you're using in Logic. The audio will automatically be transposed to the proper key.