Here’s another Ableton video with Nicolas Jaar discussing his live set-up a bit. One thing I want to briefly discuss is his point at the end of the video about changing tempo during a live set. There are essentially two good ways to do it with Ableton during a live set. The first is to simply MIDI map a controller (knob, fader etc.) to the global tempo on the upper left screen. (Midi mapping is done by hitting the ‘MIDI’ button on the upper right of the screen – when the screen turns blue, just select the global tempo and move your know or fader and it should map) . In MIDI map mode, you probably would want to hit the yellow circle that appears in the left side of the screen. That will allow you to set the parameters of the knob.
The other, and I find more useful, way of adjusting tempo during a live performance in Ableton is to simply select a clip in the Master track, hit command R and rename the clip 125bpm (Whatever number you want as long as it’s followed by bpm). Do this and whenever you launch the scene, the global tempo will follow and automatically set itself to that tempo. Absolutely crucial for live performance.