I have got an answer from the GECO team. They offer an APP that communicates with leapmotion and MIDI:
Hi Martin, GECO will require you to install a virtual MIDI interface on your computer to communicate with other software. For example loopMIDI (http://www.tobias-erichsen.de) or LoopBe (http://www.nerds.de). You can already install one of these and see if your software allows you to connect to that virtual MIDI interface. If it does, it should work with GECO. Hope this helps, Geert
Martin