Arranging : Time, Tempo, Meter, Key, and Chords : Identify Beat Command : Identifying Beats

Identifying Beats
Identifying the beat of a one-bar drum loop and creating Bar|Beat Markers for it:
1 Place a one-bar drum loop at the beginning of an audio track.
2 Select View > Rulers > Samples. This ensures that the selected audio material will be sample-accurate.
3 Select the audio clip with the Time Grabber tool and choose Event > Identify Beat.
4 In the Bar|Beat Markers dialog, specify the start and end locations for the inserted Bar|Beat Markers. Since this example deals with a one-bar loop, enter 1|1|000 and 2|1|000.
 
5 If necessary, specify a time signature for the start and end range.
6 Click OK to automatically calculate the new tempo and insert the necessary Bar|Beat Markers and meter events. Any existing tempo and meter events residing within the selection are deleted.
 
When working with a selection, the Identify Beat command only calculates a single tempo for the selected range. If the tempo varies from measure to measure, or beat to beat, you’ll need to use the Identify Beat command for each tempo variance (making sure to accurately define a precise selection range or beat location for the tempo change).
To accurately define tempos for a range of audio with the Identify Beat command, make certain that the initial selection represents an accurate length of bars and beats. You may want to first loop the selection on playback to see if it plays accurately (see Loop Playback Mode). To avoid drift, and remain sample-accurate, select the audio material with the Time Scale set to Samples rather than Bars|Beats.
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When identifying beats, select as large an area as possible. For example, if you have a four-bar-long audio file you want to identify, select the entire four bars instead of just one bar, in order to minimize rounding errors (see Sample Rounding and Edit Operations).