If you’ve spent any time in Ableton Live, you are likely familiar with “warp markers” and how they are used to mark beats in an audio file. Using these markers, Ableton can time stretch or compress an audio clip to keep it in sync with a master project tempo. It’s a very neat feature, and one of the main reasons I started using Ableton Live in the first place.
Aligning all clips to a master project tempo works great for composing electronic music, but when you’re working with a rock track of varying tempo, you might not want to impose such exacting tempo quantization to your audio clips. Luckily, Ableton can use the warp markers from a specific audio clip (ie. your live drummer clip) as a real-time control for the master project tempo. In other words, as the clip markers of your rock track indicate a speed-up or slow-down in clip tempo, Ableton will automatically warp other clips in the project to that same tempo.
Why is this cool? Well, as a mashup producer, I often times want to align the tempo of an acapella with a rock track but leave the “feel” of the rock track intact. Instead of setting warp markers on both the rock track and the acapella track and then locking both those tracks to a master project tempo, I can make the acapella track follow the tempo of the rock track instead. The net effect is that the rock track never gets time stretched or compressed, while the acapella track does.
Here’s what the manual has to say:
All warped clips in the Arrangement View have one further option: They can be defined as tempo masters by toggling their Master/Slave switches. Any number of clips can be set as tempo masters, but only one clip at a time can actually be the tempo master. This distinction is always granted to the bottom-most, currently playing clip in the Arrangement View. The clip that is the current tempo master will play as if warping was off, but with one important difference — the rest of the Live Set will be warped so that it plays in sync with the current tempo master.
This is achieved by adding tempo automation to the Master track for the duration of the tempo master clip. You will notice that the Tempo field in Live’s Control Bar becomes disabled in this state; this is because all tempo control is handed over to the tempo master clip.
Notice that you won’t find this “Master/Slave” switch in a Session view clip — you will need to copy your clip into Arrangement view to use this feature. Here’s a screenshot of a clip (in Arrangement view) that has Master enabled:
Notice the “Master” button under the “Warp” button. Use this to toggle a clip between Master and Slave mode.
With this little trick, you can breath life back into your heavily warp-markered mashup tracks. Give it a try and let me know if you appreciate the difference!