Automatically beat map regions
Logic Pro can automatically beat map audio or MIDI regions using the Beats from Region command. You can select the note value to use for automatic mapping, and select the beat-mapping algorithm.
Apply automatic beat mapping
Select the region you want to beat map.
Click the title “Beat Mapping” in the Beat Mapping track, and choose Beats from Region from the shortcut menu.
In the Set Beats by Guide Region(s) dialog, choose the note value to use for beat mapping in the Note Value pop-up menu.
The note value defines the timing resolution used to create the map.
Select one of the following algorithms:
Tolerate missing or additional events: Only tempo-relevant transients are used for beat mapping (based on the project time signature). This avoids drastic tempo changes, which are usually undesirable.
Note: This algorithm gives the best results when used with material with a regular beat, and a fairly constant tempo. However, it can also be used with material that features changing rhythmic divisions, and some degree of tempo change.
Use exactly all existing events: Every detected transient is used for beat mapping. For usable results, the regions should have an event for each tempo-significant transient.
Click OK to perform the automatic beat-mapping process.
Regions with more complex or irregular musical patterns may not initially produce useful results with automatic beat mapping. If your first attempt produces an alert saying that the required tempo would be too low, undo the beat mapping, then set the first downbeat manually before choosing Beats from Region. If the alert reappears, undo again, and set both the first and second downbeat manually before choosing Beats from Region. If this method fails, you can record a MIDI region containing synchronized regular notes, and use this as a guide region for beat mapping.
Apply beat mapping to audio material containing tempo changes
Cut the audio material at the precise position of each tempo change.
Lock the SMPTE position of each audio region.
Select the first region and perform the automatic beat-mapping process as already described.
Continue with the remaining audio regions.