I'm currently working on a project where the basic tracks are being laid down by a musician who is, for reasons beyond his control, not able to be in the studio very often. (I'll call him "Fred".) Rather than wait for when Fred can be in the studio to lay down scratch tracks, we can probably make better time if we're able to use some of the band's live recordings as scratch tracks. Then the drummer and I can get started on drums and bass and guitar until Fred can do his parts. (Not the best way to work, since it restricts us to what we did live, but it's better than not getting the album made.)

Unfortunately, this band often speeds up when playing live. The only way I know of to use those live tracks for this would be to chop up the basic tracks, wrestling them into a click-track grid. I've done this a few times, and it's a laborious, difficult process.

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Logic has the capability to take an existing recording and, using a track with a clear beat (or a MIDI track, say a kick drum) adjusting the project's tempo to dynamically follow the recording.

Is it possible to do the reverse? Take a piece of audio and time-stretch it to fit a predefined tempo? The audio doesn't need to sound great, just good enough for musicians in the studio to follow along.


It's been pointed out in the comments that Ableton Live has the capability to do this, with a feature called Warp. The equivalent in Logic is called Flex Time. As far as I know, Flex Time won't work on an entire region of audio like Warp will (I think), but I could be wrong.

To clarify: The original file has a tempo that changes as it goes on. I want to change that file so it all has a single, steady tempo.

  • I'm pretty sure the answer is yes, but my Logic skills are rusty. So I'll leave the answer credit to a more active Logic user. Feb 5, 2013 at 1:28
  • It's worth mentioning that I use Logic Express 9, but I can probably get access to Logic Pro on another computer. Feb 5, 2013 at 2:08
  • I think the core sequencer is the same in both cases - Logic Pro just comes with more plugins. Feb 5, 2013 at 4:12
  • I know this is possible in Ableton. Ableton actually does it automatically if you haven't changed the default settings after it warps the audio. Does Logic have something similar to Ableton's Warp function?
    – Travis Dtfsu Crum
    Feb 6, 2013 at 17:40
  • It has something called "Flex Time". But it's not as easy to use as I hear Warp is in Ableton Live - it's more about fixing individual notes than an entire song. My experiments with Flex Time haven't been very successful. I might be best off finding a user of Live and asking if I can run a few files through their system. Feb 7, 2013 at 2:50

1 Answer 1


I believe you can use the Flex Tool you mentioned in your comment to do what you want. Here is a tutorial explaining how:


Hitting Command + T when you have the matching number of measures selected in the cycle region, the audio clip in the track you have selected will stretch to fit the measure without effect the pitch.

However, I believe this is more easily done in Ableton Live. Download the Ableton Live demo from https://www.ableton.com/en/trial/

The Warp feature does exactly what you want to do.

I don't think any program can do exactly what you want (with large sections of audio at once) except Ableton Warp function, and Ableton's auto-warp doesn't always do it perfect. It is still quite good though and usually gets the job done. It's also much easier than Logics Flex Tool in my opinion too


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