To change tempo throughout a range (revised):
In the project window, enter “musical mode”.
Select and enable the tempo track.
Select a range in your tempo track.
Exit Musical Mode.
Drag the range up or down slightly with your mouse. This creates a tempo change point at either end of the range.
Re-enter Musical Mode.
Place the cursor between the two tempo points.
Find the “Current Tempo” box at left. Click and drag the tempo box up or down to change the current tempo.
If anyone knows where this is explained in the manual, please tell me. I had to figure it out by trial and error.
Anyway, I hope this helps someone. Btw, I’m doing this with an audio track only, with no MIDI in the project.