Apple Logic Pro 8 - Manual (Page 527)

Chapter 23 Adjusting the Tempo of Audio Regions 527
To make recorded audio files follow the project tempo (and first key signature):
m Select the audio region in the Arrange area, and turn on the Follow Tempo option in
the Region Parameter box in the Inspector.
The Follow Tempo option is synchronized for all regions that make use of the same
audio file.
All audio files that follow the project tempo (and first key signature) are indicated by
the following symbols in Logic Pro:
Note: The Follow Tempo option does not create an Apple Loop! Remember: Apple
Loops follow chord changes—should you record a solo over an arrangement consisting
of Apple Loops with transposition changes over time, you might want to enable Follow
Tempo for your solo, but you won’t be happy with the double transpositions that will
occur …