One-Step Pitch/Tempo Change

Special Interest Groups Audio Processing
1

Let’s say that I have a song, and I know the key signature and the BPM. Using Audacity, I can change either the key or the BPM of the song using the Change Pitch filter or the Change Tempo filter. However, if I want to change both values, I would have to send the same track through the stretching algorithm twice, impacting quality. Also in some cases, changing the pitch and tempo might be redundant, like pitching a song up in addition to raising the BPM. Using the Change Speed filter to raise the BPM would pitch the song up partway, lessening the amount of stretching that needs to be done.

Therefore, I suggest that Change Pitch and Change Tempo either be merged into one filter, named Change Pitch/Tempo, where you can input both a song’s original key and BPM, and be able to change the pitch, tempo, or both, all in one step. Or, this could be made into a new filter, leaving the original filters alone if that’s easier.

Let me know if this is already possible manually.

2

Change Speed adjusts both at the same time with far less quality damage than either of those two.

Koz

3

Yes, but there is no way to adjust both exactly in one step.
For example, let’s say I have a song in E minor with a BPM of 130, and I want to adjust it to F minor with a BPM of 150.
There should be a filter that allows you to do that in one step, instead of using both Change Pitch and Change Tempo, which causes twice the quality loss that only going through one of those steps.

4

There is: Sliding Stretch - Audacity Manual

5

Thank you!