Audacity 2.0.6 - How to change length

I have a stereo MP3 file I split into the left and right tracks. I’ve removed the contents of the right track and am putting in 12khz tones of a short duration on the right track. Copy and paste work well, but how do I easily change the length of the tone generated? Some tones will be longer and/or shorter than others. I was hoping to just dlick on the right (or left edge) and drag it shorter or longer but that does not work. I’ve searched the doc but can’t find an easy way to do it. Anyone have any ideas?

Btw, I’m driving a 3-axis skull for halloween and the tone helps with the jaw movement. The tone needs to coincide with the timing and length of the voice in the left track.

If you select the part of the track where you want the tone, then “Generate > Tone” will automatically produce a tone that is the correct length to fit the selection.
“Select” the region by clicking and dragging along the track where you want the tone.

Yes, I understand I can do that. I’ve got a lot of them to do and was wanting something faster. Copy and paste, then changing the length by dragging an edge would be the quickest way, but that doesn’t seem available. Any other quick method?

That sounds like a job for “Punch Copy / Paste”
Instructions for installing Nyquist plug-ins are here: