Keystrokes with MIDI for Live Performance, in Ableton
One of the things that has always drove me crazy with live performance is getting tied down to a laptop; finding yourself hovering over the machine and nodding your head, instead of losing yourself in the moment and engaging both yourself and your audience.
Part of it stems from the first couple of shows I did, that weren't live loop based. I essentially was doing just that, sitting in front of my computer and occasionally hitting a couple of buttons. It occurred to me that I could be doing anything up there, checking my email, looking at porn. It's what led me to continue to explore looping for my live performances.
One of my cardinal rules is a sort of "laptop-as-a-hot-potato" thing, essentially trying to make interaction with the physical laptop as minimal as possible.
There are occasional tasks that are unavoidable, but certain things that are keystroke only, I did manage to work around into my MIDI controllers.
Like I've mentioned before I use Bome's Midi Translator for a lot of automation and chained MIDI message handling. One of the magical features it has is the ability to convert MIDI messages into keystrokes, enabling you to do stuff like duplicate clips in Ableton (⌘-D) with the press of a button, instead of touching the keyboard. (For a free solution, I believe MidiStroke may still work)
You can really apply this to anything you can think of that has a keyboard shortcut, and even a few things that don't have keyboard shortcuts, to boot.
OSX's Keyboard Shortcuts Feature
One of the things I like to toggle a lot during live Ableton performance is quantization. Depending on what I'm trying to do it's nice to be able to fall back on a nice Sixteenth Notes-and-Triplets foundation, but have the option to make things more organic by toggling to No Quantization mode.
One of the unfortunate things you'll notice when you go to Ableton's Edit > Record Quantization menu, however, is that Ableton doesn't ship with key commands to change the quantization settings. It's a bummer, but in OSX (and if my memory serves me correctly Windows as well), you can actually define your own key commands for situations like this.
If you go to System Preferences > Keyboard > Keyboard Shortcuts, you can assign your own key commands, or even modify existing ones in programs if you don't like them. Case in point—I'm always accidentally hitting ⌘-Q while I'm working so I've actually got some programs set to only quit if I hit ⌘-Shift-Q now.
To add a new command you'd hit the plus button, select Ableton from the Application list, and then type in the exact text from the menu item you want to shortcut. For example, I want Sixteenth-Note and Triplets Quantization, so you'd have to type that exactly in order for OSX to match it.
Once I've got that in I assign ⌘-Shift-X as the key command, and hit add. You'll see it added to the list, and if you reload Ableton, you should see it there now as well.
From here I do the same thing for No Quantization, but set the key command to ⌘-Shift-Z.
After that, it's just a question of setting it to the controller and MIDI message you want in Ableton. I prefer a single toggle button on my KORG Nanokontrol, so I've got one rule in Bome's that triggers ⌘-Shift-X on MIDI ON, and a second rule that triggers ⌘-Shift-Z on trigger off. Just like that you've got toggle quantization!
There are a lot of other things you can do, that's one big example of what I use it for, though!
Update, April 25th 2014: For those of you that are Max for Live capable, here's a more elegant solution from AfroDJMac, for changing quantization with MIDI: afrodjmac.com/2013/07/31/quantize-mapper-fixed-for-ableton-live-9-free-ableton-live-pack-86