Apple Logic Pro 9 - Manual (Page 1042)

Beat Mapping Audio Regions
Beat mapping audio regions works in a similar fashion as it does for MIDI regions. The
main difference is that Logic Pro must first analyze audio regions in order to find
rhythmically prominent spots, which can subsequently be linked to a bar position.
Logic Pro searches for transients when analyzing audio regions. Transients are positions
where the audio recording becomes a lot louder—over a very short time span (a signal
spike, in other words). This is typical of drum recordings, but the analysis of other
instruments or complete mixes (depending on the musical context), can also produce
usable results.
To detect transients in audio regions
Do one of the following:
µ
Select the regions that you want to analyze, and click the Detect button in the track
header of the Beat Mapping track.
µ
Drag the regions onto the Beat Mapping track.
Following analysis, the transients are displayed as small vertical lines at the bottom of
the Beat Mapping track.
Tip: It can sometimes be difficult to identify transients, due to the waveform overview
being too small. In this situation, you should use the Waveform Zoom button, found to
the left of the horizontal zoom control in the Arrange area. This allows you to visually
resize the waveform in the Beat Mapping track.
The remaining steps of the beat mapping procedure are as described for MIDI regions.
For details, see
Beat Mapping MIDI Regions .
1042 Chapter 34 Beat Mapping Regions