SyncLock Tracks - the biggest mystery of them all!

I am desperately trying to understand this feature of Audacity. I feel sure that, if I can master it, it will be of enormous benefit to me. However my tests are not going well.

  • I launch an Audacity project with six stereo tracks in it. I add a label track and move it to come after the first three stereo tracks. I add a label to the label track (Ctrl+B). I key the value “a” (without quotes) into the label. The label is aligned opposite the middle stereo track of this upper group of three tracks.
  • I add another label track and leave it at the bottom of the window. I add a label to the label track (Ctrl+B). I key the value “b” (without quotes) into the label. The label is aligned opposite the middle stereo track of this lower group of three tracks.
  • I deselect all tracks (Edit > Select > None). N.B. This was done because Gale, in another topic advised that SyncLock Tracks was not about “selectedness”)
  • I engage SyncLock Tracks via the Edit toolbar button.
  • I select the Timeshift tool.
  • I select one of the three tracks by clicking in its Track Details panel. The SyncLock icon appears in the Track Details panel of all three plus the label track. The background of the two “not selected” tracks in this group is filled with SyncLock icons. This all means that when I do the Timeshift, all three tracks and the label track will move together, right? Wrong!

Only the selected track and the label move. The other two tracks do not move.

Perhaps I should not have selected one of the tracks before Timeshifting. I deselect all again. The SyncLock icons go out everywhere. I Timeshift the top track – and the second track and the label track also move – but not the third track. So I’ve got a sort of group but not the group I thought I had defined. I Timeshift the third track. The label track moves with it but not the first or second tracks. So, I’ve got two groups where I thought I had one and neither of them is the one I want. And the SyncLock icon is out on every single track.Where’s the logic in all this? All it is doing for me is confusing the hell out of me!

Please can somebody give me precise, step-by-step instructions to set up a SyncLock group and then Timeshift all the group members. All I ask is that it is a guaranteed, repeatable process that will work with any number of participating tracks and can be replicated to give more than one group within a project!


Please post an image of the track layout. I don’t know what you mean by the label is “opposite the middle stereo track”. It shouldn’t make any difference to explicit Sync-Lock behaviour, but are the start of all the audio tracks aligned with time zero, or you spreading the tracks out like a military cohort again? What time is the label aligned with?

Again, I cannot visualise this.

Selectedness neither defines groups, nor prevents tracks being in groups. There is no need to deselect tracks to make Sync-Lock work.

There is no need to add a label to a label track to define a group, the presence of the label track is sufficient.

You only need one label track placed between the audio tracks to define two groups, the groups being demarcated by that single label track.

Makes no difference.

Your project is broken or you have a precise setup that we cannot see that is causing a bug.

I have discounted that you were not dragging over the audio of the track, because that would cause nothing to move.



I have simplified what I was doing to reflect your comments above. The situation is now as follows:

  • File > Open Audacity project file

  • Resize window to keep image file a reasonable size when posted on forum

  • View > Fit Vertically

  • Screengrab SyncLock01 (see below)

  • Tracks > Add New > Label Track

  • Drag label track to come after the third track

  • View > Fit Vertically

  • Click SyncLock button in Edit toolbar

  • Screengrab SyncLock02 (see below)
    It is my understanding that, at this point I now have three tracks (the top three) that will participate as a group under SyncLock control. So, if I now Timeshift any of those three, the other two will move with it, thus preserving their “locked synchronicity”. Right? Wrong! Whichever one I choose to Timeshift, that is the only one that moves. As my first Timeshift attempt I dragged the top track to a point where it overlapped the second. It was the only track to move. I then dragged the second track and…

Eureka! The tracks move as a group ONLY if they overlap one another. They do not move as a group if they are spaced out with no overlap. So SyncLock does NOT preserve synchronization of tracks.

If this isn’t a bug, it is most certainly a design weakness. Obviously, I can get a workaround by generating a tone track that covers the entire length of my project and dragging that into the group. For the occasions when I could usefully use SyncLock, that would be acceptable but I’d rather see SyncLock work like I think it should - locking them whether there is overlap or not.

Thanks for your patience in getting me this far.

Or rather, it preserves synchronization of sound against sound but not of sound against timeline. It has implemented a very narrow definition of “synchronization”.

I am now able to answer my own plea.
To set up a group that will participate in SyncLock proceed as follows:

  • Add Label tracks and position them in the stack so that they delineate the groups that you want to have
  • Generate a Silence track that extends the whole length of the project and position this track within the group that you want to Timeshift
  • Activate SyncLock
  • Timeshift as required using any of the tracks within the group.

Note that the Silence track will move as you Timeshift your target tracks. If you intend to move another group by a different amount or in a different direction, the safe thing to do is to delete the Silence track and add a fresh one, positioned into the next group to be Timeshifted.

The manual page for SyncLock is, in my opinion, incorrect and misleading. I quote:
"When Sync-Lock is on, an icon (image of sync-lock icon) shows bottom right in the Track Control Panel of each track in a Sync-Locked group, provided at least one of those tracks is selected. The icon denotes all tracks that will be affected when a menu operation in a selected track inserts or deletes audio (or otherwise changes the audio’s position on the Timeline). The unselected tracks that will be affected are denoted by a patterned “Sync-Lock” selection in the waveform instead of the dark grey of a normally selected track. "

The incorrect part? “…or otherwise changes the audio’s position on the Timeline…” True only if this audio overlaps with audio in another member of the group. If it doesn’t overlap with any other group member, this track will Timeshift on its own without causing the rest of the group to move.

The misleading part? “…provided at least one of those tracks is selected. The icon denotes… when a menu operation in a selected track… The unselected tracks…a patterned “Sync-Lock” selection in the waveform instead of the dark grey of a normally selected track…” Five uses of the word select or its derivatives in one paragraph; and yet “selectedness” plays no part in the operation of SyncLock. That is not the understanding which this paragraph gives me. Quite the reverse, the frequency with which the word is used tells me that selection is a key aspect of using SyncLock.

I feel that the SyncLock Tracks page in the manual needs more detail as follows before diving into the detail of how to use it in different edit tasks:

  • Instructions on how to define a SyncLock group
  • Instructions on how to add or remove tracks from the group
  • Instructions on how to switch the focus of SyncLock from one group to another
  • A reminder that the setting of SyncLock Tracks is pervasive across a stop-start of Audacity.

Thanks, Peter.

As far as I can see, all that is needed is for the “extra track” to contain audio that overlaps (not just abuts) all the clips in the group.

Note that any labels in the group always time shift, even if there are no overlapping clips or if the labels do not overlap with any clips.

Another solution is to select in all the tracks in the group from time zero so that the selection at least extends over part of the final clip in the group. Then drag from somewhere within the selection. That behaviour is identical whether Sync-Lock is on or off, except that if Sync-Lock is on, the label will move even if the selection is not over it.

I’m not sure but I have a feeling the behaviour you are complaining about could be deliberate, so as to give more “flexibility” when using Sync-Lock. I agree this is not documented, and the workarounds if you want to drag all the tracks seem counter-intuitive; I would expect to turn Sync-Lock off I wanted to drag a track on its own. I’ll raise it for discussion (but if anything does change, it probably won’t be until well after 2.0.2).

I also found a repeatable crash in a project I set up to look at this, though it seems to require selecting over the clips (as described above) then sync-lock dragging a clip into another track before dragging all the clips to zero. If you see a similar crash again and the steps are different, please advise.


Agreed. I was just keeping the procedure as simple as possible and as “idiot proof” as possible when I suggested making that extra track cover the entire project.

Can I suggest, as a “stop gap” until those deliberations are concluded, that the manual be modified (as soon as possible after 2.0.2 freeze is lifted) to have the following added:

  • a warning that tracks that do not have overlapping sound may not perform as expected under SyncLock state
  • a Tip that adding to the SyncLock group a Silence track that spans beyond the extreme edges of the SyncLock group, will ensure that all members of the group then behave as expected

Will do!

I’ve got repeatability, too! Starting from the same point as before (second screen shot above) I simply dragged the clip on the middle track of the SyncLock group straight up into the top track of the group - and bang!
Do you need any diagnostics from me? If so, what?
N.B. I’m running Win 7 Home Premium 64-bit with Audacity 2.0.1. Presumably you’ve checked 2.0.2 RC and the bug is in there too?

Thanks, yes I boiled the issue down just to dragging a clip into another track, if a label track is present. It’s an old bug, fixed once for 1.3.14 but it resurfaced for 2.0.0: .

IMO, selecting over the clips is a much easier way for user to understand the workaround for dragging all clips in a sync-locked groups, but we have, so selecting over clips is not really a good idea at the moment.

I’ll look at the Sync-Lock page in the Manual after 2.0.2.


Could you please clarify what you mean by “selecting over the clips”? Do you mean doing a dragged selection where the drag has travelled both horizontally (across several clips) and vertically (across several tracks)?

If so, that is a workaround of limited value for me with my soundtrack assembly projects. I usually have at least two screens of tracks and often more and the tracks are always laid out in echelon formation. My two most recent projects both had 49 stereo tracks. On the first of those I arrived at a point where I needed to move all except the first three tracks 35 seconds further along the timeline (whilst preserving the already established synchronizations relative to one another). I don’t know of a slick way to drag-select across a screen boundary. If there is one, please tell!

I mean a selection that at least part-encompasses all the overlapped clips that one wants to move simultaneously.

It’s an open bug that dragging a selection vertically doesn’t scroll the project.

If you want to all the clips to move then CTRL + A to select all seems simplest.

If you want to prevent some clips moving when others do, SHIFT-click on the Track Control Panel of those tracks to deselect them. SHIFT-click again to reinclude those tracks. To do this with the keyboard, use UP or DOWN arrow on the keyboard to move the focus border to the track you want to deselect, then press ENTER. Repeat for the other tracks you want to deselect. If a track you want to deselect is adjacent, hold down SHIFT then use the appropriate arrow key.

SHIFT + UP or SHIFT and DOWN do actually scroll the screen vertically, so are a solution until dragging scrolls vertically.