Cheers, though I should probably have said that I already have this working. I've used OSC with Unity in the past, as OSC is what the Jazzmutatnt Lemur spits out, and other stuff such as bridges to things like Wiimote data, TouchOSC iPhone/ipad application and the initial kinect skeletal tracking stuff I messed with (before a proper kinect/OpenNI wrapper for Unity came out). Someone took some OSC code and made it work in Unity, and I've gotten to grips with how this script works and modified it as necessary.
In a nutshell each Eigenharp key is sending pressure, roll and yaw data via OSC as a series of floats, and I am then obviously free to use these floats to control whatever I like in Unity in the normal way. Today I got sick of some of Eigenharps own way of outputting MIDI, so I've just started using Unity to generate the actual musical note data as well. Works pretty well using a Unity MIDI plugin I purchased via the Unity asset store a while ago. I'veknocked something up so I can play the eigenharp in a way thats more like a guitar than the instrument normally works. Some keys are being used to select the note or chord to play, and another key actually triggers the note, determines its volume etc.
Anyway hopefully I'll get onto the fun bit soon of actually visualising it all in an interesting way, hope my creative side doesn't let me down as all too often I master the technology only to discover that my original idea was somewhat vague. I hope the video of my results will be a lot more interesting than my usual lengthy forum posts!
Any particular area of Unity that you enjoy the most or consider to be your main strength?