I guess until it gets moved, I could ask you about this: I am using PD438C/S46 photodiodes. I did wire up one of them and irradiated it with a laser pointer and it does turn on/off LEDs as the beam is interrupted.
Is it possible (do you think) to get this sensor to do double duty by turning off the MIDI note when the laser is present and turning on the MIDI Note AND reading the "proximity" of the finger to bend the note appropriately?
Photodiode datasheet here: PD438C Datasheet(PDF) - Everlight Electronics Co., Ltd