Tempo map changes and automation

I attach 2 screenshots of a short test file, using qtractor 0.9.36.

Before.png shows the file after adding some simple volume automation, with the nodes approximately at the start of bars 3, 4 and 5.

After.png shows the same file after making tempo changes at various points. I found that changing the tempo mostly did not affect the placing of the automation nodes relative to the music, but when I changed the opening tempo (Bar 1) that threw the automation out of sync., as shown. If this were generally true then there would be an easy workaround: simply have a silent bar or two at the start of the piece (which I normally do anyway) and set the actual required opening tempo a bar or so later.

Unfortunately further experimentation has shown me that intermediate tempo changes also sometimes (but not always) throw things out of sync. Reversing those changes does seem to revert things to how they were before the change was made, but again, I'm not 100% sure whether that is always true. Neither can I understand why some changes wreck the synchronization, and others don't.

Using midi velocity is not a solution, I'm afraid. In fact, I do make most of my changes using velocity. But, as I understand things, it is not possible to alter the velocity of a note once it is sounding. So far as I can tell, then, the only way to produce effects like sforzando-piano on a note, or a crescendo through a long note is to vary .the volume. Those are the only times I resort to doing this: I do everything else regarding loudness changes by adjusting the midi velocity of notes.

David

As I mentioned previously, in my small test file I found that the automation stayed correctly aligned with the beats whilst I made several changes. just as yours did. But when I changed the opening tempo (i.e. Bar 1) I got the messed up version shown in my second screenshot. I can't remember the exact changes I made or in what order. But the final change - the one that caused the mess - was definitely at Bar 1.

I thought that this might mean that it was only Bar 1 tempo changes that ever cause a mess, and I could easily work around that. But since my previous post, I have experimented with making tempo changes in my actual project, and I find that tempo changes at intermediate places in the music can also cause the automation curve to end up in the wrong place. I have just tried this again: in my main project, I changed the tempo of a single bar from 152 to 160, and the volume curves later in the movement ended up in the wrong places. When I changed this bar back to 152, the curves were restored to their correct places.

I can't wait to try out your latest version to see whether it has solved the problem!

Slightly OT, but I'd be grateful for your advice: if I do 'git pull origin develop', do I have to do a complete recompilation, or is there some way to short-cut this and just install the changes?

I have spent some time editing my main project this afternoon, using qtractor v,0.9.36.13git.6c4f5a. I used the new legato and articulation options, which are very useful, but more importantly I moved my few bits of volume automation back to their correct places in the music.

Unfortunately I find that there are still some weird things going on with tempo changes. When I make a change in the Tempo Map, I often find that another unwanted change is made, either earlier or later in the music than the actual change I made. I have also found the the automation is now all out of place again.

Over the next few days I'll try to make a short test file and then make a note of every change I make, and any unwanted side-effects that occur. Perhaps that will help to pin down exactly why these strange things are happening.

David