Making things non-contact has been the trend nowadays.
I created a simple midi controller using Arduino Pro micro and some IR-proximity detectors board which has an in-build comparator , this should be available fairly easy and cheap. This project can be used on any Arduino which has 32u4 based board, this was done due to the ability to use these board has MIDI without the head ache you have to go through using hairless midi and the glitches associated with it. This project was done for 7 major notes which could easily be extended for other notes. I used calkwalk by bandlab as my DAW because its cool and free.
Hope you have fun making this. This project was initially designed to introduce students to the beautiful world of Infra Red and its fun application.