Tempo changes don't seem to actually change the tempo

I’m using Ardour6 from the Linux Software Manager.
Tempo changes don’t seem to actually change the tempo. I have both midi and audio tracks and if I add a tempo change, neither the playhead nor the tracks change speed.
All I can see tempo doing is changing the grid spacing on the project grid.

Tempo changes are for changing the tempo of the grid and the click.
If you enable the metronome you should hear the change.

If you want to change the tempo of already recorded audio you’ll have to do a time stretch

I’m not sure how to change MIDI tempo; it should in theory adhere to the tempo change but maybe it doesn’t.
Or maybe it’s just that your Ardour 6 is rather old and that it actually works in Ardour 7.

Yes the metronome changes with the grid, but that’s not any use if the events aren’t being altered. I came from two decades of Sonic Foundry/Sony/Magix Acid so I’m used to setting a tempo change and the playhead is what changes speed to play the sound/MIDI events faster/slower, the grid nor none of the events change length. This seems not only backwards, but makes tempo changes a completely manual process.

  1. In Ardour, audio tracks will not change in any way when you change tempo.

  2. In Ardour, audio material played from the cues/clips tab/page will change to follow tempo.

  3. Changing the visual extent of a MIDI event when the tempo changes is the way almost all contemporary DAWs work, including Ardour. If the tempo increases, the duration of the events (and placement in time) will alter relative to wall clock and/or audio time. This means they will get shorter in terms of visual presentation (just as they do when you hear them).

“1. In Ardour, audio tracks will not change in any way when you change tempo.”

If that’s the case then Ardour’s tempo change isn’t a tempo change, it’s just a ruler change. The tempo speed should operate exactly as the Shuttle Speed does.

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Sorry, but we disagree.

The category of program you’re referring to all do time-stretching-without-pitch-shifting as part of their basic model of operation.

Ardour does this for the cue/clip page, but not for regular tracks.

The shuttle controller does speed-control, which also changes pitch, which is generally undesirable for the purposes you almost certainly want.

The more accurate thing to say is that audio tracks in Ardour are tempo insensitive.

It’s also worth pointing out that while modern day time stretchers/pitch shifters generally are quite good they nevertheless do introduce audio artifacts.
So if you decide to change the tempo you should at least consider re-recording any affected audio.

I just bought 7.3 and while it fixed the first midi note bug, it still didn’t fix this.
I dropped a song into a stereo track, cut it into clips. Slid the clips so that there were quarter notes between them at 120bpm.
If the audio events doesn’t change speed with the tempo (at least without some kind of setting in their properties menu) then fine. But they still aren’t being tempo’d with the project.
I then changed the tempo to 200bpm. The ruler changed so now there were no longer quarter note gaps between them, and when I play the project the events play out exactly as they did with the 120bpm, complete with the original quarter note spacing at 120bpm they had, except now the project is at 200 and I would have to manually slide each of these events to new respective locations in order to make them play out at 200bpm. This is the problem caused by the project timeline changing instead of the playhead speed.
Why is this an issue? Because if I use sample audio clips of drum components instead of MIDI triggers to a VST sampler to make my drums (i.e. a track for the kick, a track for the snare, and a track of everything else) and I arrange them the way I want and C+P them as a group down the timeline and then come to a tempo change, I have to manually rearrange these clips to the new ruler instead of the playhead just playing faster.

No, you need to wait for 7.4 …

At present, you cannot lock audio clips to beat time, so they are not only internally tempo-insensitive, but also positionally-tempo-insensitive (this was not true in 6.x and earlier, but one of the whole major features of 7.x has been a complete reimplementation of how we handle time & tempo)

In 7.4 you will be able to mark a track as using beat time, and once this is done, then the positions of regions within the track will follow the tempo.

7.4 will also feature functioning tempo conforming, which is “currently” of more interest (fitting the tempo map to a human performance)


:open_mouth: :people_hugging:

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I just recorded a guitar line to a synth I set to a loop region at 120 bpm.
I didn’t like the feel of it, seemed too slow. So I muted everything but the metronome, set tempo to 140bpm and went to practice to the loop region.
Because the ruler changed instead of the playhead speed, the loop region was now off and looping on a completely wrong downbeat.
I would ask if this was some intellectual copyright thing (such as photoshop vs Gimp’s un-intuitive aesthetic) but you just said you’re addressing it in 7.4.

You seemed to have come to Ardour with a vision that everything is locked to beat time (and thus tempo).

This is not the case. It is the case (at least by default) in the set of DAWs or DAW-ish tools that you mentioned, but it’s not true in many other DAWs (including ProTools, Logic, Digital Performer and … Ardour).

At present in Ardour most things use audio time, which means that they do not change in response to altering tempo or the tempo map.

In earlier versions of Ardour, more things could be (optionally) locked to beat time, but as of 7.3, MIDI is more or less the only thing that is. Future versions will restore the ability to say, for example, “this loop uses beat time” and will therefore respond to tempo changes.


It is a design philosophy or design analog thing. Think of the Ardour design as an analog to a digital tape recorder, and a separate MIDI sequencer. When you change the tempo you change the tempo of the MIDI path, but that doesn’t change the tape recorder. At least historically, it sounds like Paul is working on extending the model, but at least currently if you think of it as a tape recorder with associated MIDI sequencer it makes more sense than trying to think of it as some kind of sampler or Akai MPC style device.