You don’t usually do this manually, but use Region > Edit > Rhythm Ferrret to analyze and find onsets or transients.
What edit-point are you using? Is it over the selected region?
Select one (or more) regions, then move the Edit Cursor (usually the playhead) on top, and add a transient marker. A gray line will appear at the edit-point in the selected region(s):
The main effect is that it will act as additional stop when you Transport > Playhead > Move to next/previous transient (ctrl + arrow-left/right).
It will also be used as additional split-point when you use the Rhythm ferret.
You can select and drag a transient maker with the mouse to move it, and use shift + click to delete it.
Ah, that was the problem! No, I had the playhead as edit point, and it was outside the region. Moving it into the region first worked, as did switching to mouse as the edit point and moving the mouse inside the region. For better UX there should be some kind of warning when you try to use this to place a transient outside a region, e.g. a simple “place the edit point inside the selected region first” popup.
Thanks. That is all super useful to know; I guess now I should submit a PR adding it to the manual as a thank-you… but first is there any chance someone could reassure me that such a PR would have a chance of being reviewed? The current list of open PRs makes me slightly worried that I might be wasting my time.
Weird, I can’t even reproduce this now. I think it must have been some weird heisenbug.
One possibility is that I had a different track selected to the one which my mouse was over, so I was expecting the transient to appear in the wrong place.
I have noticed two minor bugs (or at least oddities) with this feature:
Deletion doesn’t work in the upper half of the track if Smart mode is enabled.
When I hover over the transient, the mouse pointer changes into a cross, but sometimes the grey line changes to a red highlight, and other times to a blue highlight. I can’t immediately see any difference in behaviour between the two.