Framed Laser Harp + Synthesizer

Hey everyone! My team and I are planning to build a framed laser harp for our senior design project. We have a team of 4 electrical engineering students and 2 mechanical engineering students. The ME students will design the frame. I'm one of 4 EE students and our task is to design the circuit and implement it.

So here is our design ideas. We are going to have 35 laser diodes and have 5 independent harp sections, so that each section of the laser harp will have 7 laser diodes. The sections and lasers will be aligned in a chromatic musical scale. We are planning to use an Arduino UNO microcontroller for each of 5 sections, so there will be 5 Arduino boards each controlling 7 lasers. We also want to be able to control the dynamics of the sound, so we are planning to somehow synchronize the circuit with a synthesizer or some computer program.

I would appreciate any help on how to start the circuit design, electronic components, and everything else that would help us to start prototyping it and testing the circuit. Thank you very much!

You've made a big thing about the lasers.
What about the detectors? They're far more important, surely?

Have you got past the (forgive the pun) hand-waving stage?

Yes, detector circuit is another thing we need to design.

No, we haven't gotten past the hand-waving stage... Nothing has been done yet. Everything is on the paper.

We need some help to understand how to produce a sound and which circuit elements would help us achieve the results and actually design the circuit schematic.

Thank you!

Google "midi" (ignore any references to the south of France)