# Sliding Stretch

From Audacity Development Manual

Sliding Stretch... allows you to make a continuous change to the tempo and/or pitch of a selection by choosing initial and/or final change values.

Tempo changes made without selecting a pitch change preserve the original pitch, and pitch changes made without selecting a tempo change preserve the original tempo. By changing only one of tempo and pitch and choosing the same initial and final value, you can use Sliding Stretch in the same way as Change Tempo or Change Pitch to produce a high quality fixed change. However Sliding Stretch lets you for example set the initial tempo change to -50% while also setting the final tempo change to +20%, the initial pitch change to +3 semitones and the final pitch change to +1 semitones.

Because of the high quality algorithm used, Sliding Stretch is normally slower compared to performing the same effect with Change Tempo or Change Pitch.

  Accessed by: Effect > Sliding Stretch...

## Tempo Change

Initial and final tempo change values can be managed using the slider (which will move in whole number values only) or by entering a value in the box, which can be either a whole number or a number including a fraction.

### Initial (%)

The percentage of the original rate required for the beginning of the processed audio. Positive percentages speed the audio up and negative percentages slow the audio down: -50% is half-speed, 0% is unchanged, 50% is 1.5 times the original speed, 100% is double speed and so on.

### Final (%)

The percentage of the original rate required for the end of the processed audio.

## Pitch Shift

The two "Initial" input boxes are interdependent. Entering the required value in one of the boxes for Initial Pitch Shift will automatically display the equivalent value in the other Initial box. Similarly, entering a value in either "Final" input box will display the equivalent value in the other Final box.

### Initial (semitones)

Enter the pitch shift in semitones (half steps) required for the beginning of the processed audio.

### Initial (%)

Alternatively, enter the pitch shift as a percentage of the original frequency as required for the beginning of the processed audio.

### Final (semitones)

Enter the pitch shift in semitones (half steps) required for the end of the processed audio.

### Final (%)

Alternatively, enter the pitch shift as a percentage of the original frequency as required for the end of the processed audio.

## Buttons

Clicking on the command buttons give the following results:

- Manage gives a dropdown menu enabling you to manage presets for the tool and to see some detail about the tool. For details see Manage presets
- Preview plays a short preview of what the audio would sound like if the effect is applied with the current settings, without making actual changes to the audio. The length of preview is determined by your setting in Edit > Preferences > Playback, the default setting is 6 seconds.
- OK applies the effect to the selected audio with the current effect settings and closes the dialog
- Cancel aborts the effect and leaves the audio unchanged, closing the dialog
- brings you to the appropriate page in the Manual, this page

Time Tracks can be used to bend tempo more flexibly (also affecting pitch) using the Envelope Tool.

## Links

|< Index of Effects, Generators and Analyzers

|< Effect Menu