Gestural control is apparently the next development after touch (Minority Report has a lot to answer for), beyond that, we're heading for mind control. The Leap Motion is one of the first mass-produced devices that enables two-handed, multi finger control in 3d space and it's pretty cool. GECO is an app (available via the dedicated Airspace Store at $9.99 ) that takes advantage of this control and allows you to map multiple control to MIDI.
Developed by Geert Bevin, you may know him from his work with the Eigenharp, he's a kind of music/software futurist developer who's pushing the boundaries with this new technology.
Installation is a breeze with the Airspace App store and control centre, now it's just a matter of configuration. Well perhaps first, you should get familiar with what it's actually like to use gesture control with the Leap Motion, it not being an altogether intuitive experience.
Once you've done swiping fishes about and wondering placidly amongst some of the demo apps, You can get into Geco - basically you get control for L/R, UP/DOWN, FORWARD/BACK, TILT for each hand, plus open and closed - Geco can detect whether your fingers are together or spread, while the Leap Motion can do individual fingers, it's not that granular in Geco. Even so, thats a lot of controllers to get your head around. It's then a simple matter of identifying the axis you wish to use, double click on the relevent button and assigning a MIDI channel and a control number. You can also set the rest value: default assuming you are not controlling, eg: Controller 88 at 35% etc, etc.
It is also possible to set an offset so that a zero point might be where your hand is most comfortable.
GECO has a pretty clean interface, it's not hard to setup and MIDI commands can be sent via Port accessible in your DAW or instrument as a MIDI port, or routed to an existing port, or sent over OSC. CopperLAN is also supported, but we don't have any devices here that work with that protocol.
It's actually a lot of fun to play with, my only real problem is more that I just don't really have the vision to see how I can use it in my world, but that could well be an issue with my poor imagination. The performance artists amongst you will no doubt see the potential for live gestural action where it could well be a perfect fit.
Geco is limited to control values only, perhaps notes or chords would enhance the experience - according to Geert - this will be coming - future developments in the Leap Motion OS will allow thumb and forefinger touch events etc which would make sense for MIDI note/event triggering. But for now, at least for me, gestural control is for others to pioneer in music and me to watch until I see a must-have use for.
It's one of those things that some of you will immediately see how to apply and use this. I can't wait to see those applications. The app is nicely designed and simple to use, as for gestural control generally, I'm not convinced... yet.