Curve diagram for pitch and speed

I think it would be useful to have a curve diagram for the pitch and speed of a whole track.
This would make it a lot easier, if you want to change the pitch/speed of different parts of a track individual.

You can do that in Audacity 1.3.5

“Tracks > Add New > Time Track”

Thank you!

Does there also exist a tutorial, which explains how it works?

I had a quick look, but didn’t find one. It’s pretty simple though.

Click on the track name to set the range, then use the “Envelope Tool” to move the “speed line” up and down. Going higher makes the audio play faster and higher pitch, going down makes it slower and lower pitch.

To permanently apply the changes to one or more tracks, use “Mix and Render” with the track(s) that you want to affect selected. (and delete the time track when you have done so that it is not applied again).

Note that it does not respond well to sudden large jumps in speed, at least, not on my computer.