Stretch Tab

This tab is used to control stretching or compressing in time to accommodate a project s tempo. One-Shot tracks and files are primarily used for media that should never be altered in duration thus, the Track Properties window in this situation does not have this tab. There is a lot of information on this tab for Loop and Beatmapped tracks, however. 

The Root Note is the key of a loop. This property of a track can be changed on the Stretch tab in the Track Properties window of Loop and Beatmapped type tracks. The Root Note allows a track to be automatically pitch shifted to match a project or the key changes that occur in a project as a result of Key Change markers. Setting the Root Note to Don t Transpose prevents this from happening. Any time you want a loop to be protected from key changes, you should select Don t Transpose. You ll notice that most percussion and drum loops have Don t Transpose as a Root Note, as well as some vocal loops and, especially, spoken word loops. 

The Stretch tab for loop-type tracks and files sets how ACID adjusts the loop when it is inserted into a project. It controls the tempo and where the beats fall. For loop fdes, ACID stretches and compresses smaller subdivisions in the file to force the beat to match the project. This means that the playback of a loop file may vary over time. Here is what you will find on this tab  

The Stretch tab of the Ttack Properties window for a loop file. 

Zoom in to get a better look at the orange beat (transient) markers. 

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Loop tracks and the media files that they contain that come from Sonic Foundry have beat, pitch, tempo, and type information saved with the file. Any audio files below about thirty seconds in length will be inserted as loops into loop tracks, with ACID s best guess about the beats and tempo. Pitch information will not be included, although pitch is an important aspect of Loop tracks. This is because Loop tracks can be pitch shifted automatically or manually. The Stretch tab in the Track Properties dialog is used to control this information. While most loop files contain pitch information, this is not really necessary for loops that are not primarily tonal in nature, such as drum and percussion parts. Most percussion loops are inserted as loops into Loop tracks and can have pitch information added, but they do not have a root note selected on the Stretch tab. 

Outside the Beatmapper Wizard, the Beatmapping of a media file as it is inserted into a track can be adjusted in the Track Properties window on the Stretch tab (see Figure 9.4). The first downbeat and measure adjustments can be adjusted while the main project is being played back to align the media in the Beatmapped track with the project. Use a simple drumbeat to compare the project tempo and beat with the Beatmapped track since there is no metronome associated with this window. 

The Stretch tab for Beatmapped tracks and files is basically a way to manually modify the characteristics that can be set using the Beatmapper Wizard (see Figure 9.4). 

Click the Beatmapper Wizard button on the Stretch tab in the Track Properties window. 

The new loop file will be saved to your hard disk with the name you have selected. Remember to press F5 in ACID s Explorer window to refresh the window and see any new files. The newly rendered loop will have a tempo that is equal to the project s tempo in beats per minute and will automatically be a loop track if it is between the default durations of 0.5 seconds and 30 seconds. The Number of beats on the Stretch tab will be four times the number of measures of the loop region in the project (four beats per measure). The root note will be the project s default key, but this will have no bearing on the actual key of the media file itself. 

Once you have determined the tempo, you may want to change the track back to a Beatmapped track armed with this new tempo knowledge, which you can add to the Stretch tab in the Track Properties window. Click the Save button in that window to save the tempo information with the file. 

Technically, Loop tracks do not have a tempo adjustment, but the Number of beats item on the Stretch tab in the Track Properties window can control the speed of playback in a rough way. Loop media files are recorded at a set tempo, however, and, as with other ACIDized media files, this information is saved with the file. The Save button in the Track Properties window does not save Number of beats or tempo information for loop files. 

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