I build music robots for many years already. Music Robotics is a broad field involving acoustics, electronics, mechanics, programming and music (obviously!). And there are gorgeous projects out there, and its easy and fun to start!
For the building logs I picked out one of my favorite instruments, the futuristic kalimba, and I will walk you through my building process!
I start from the musical side: what do I need in the musical context? Most important in electronic music is Bass! Because Bass is the mother of all sound!
So what do I want, soundwise? Undisputed, the most iconic bass sound in history of electronic music is the TR-808 Bass drum sound. Let’s try to replicate that - with a robot. First I looked at how the 808 bassdrum actually sounds:
As a starting point I also look at the circuit. One can see in the circuit (or read somewhere) that I consists of a Sine Wave + an envelope. That should help us later.
Bass sounds are appearing at a lot of places in the real world. I got used to walk though the world with open ears and listen to all different sounds that you can find in daily life. "I could always need that special metal piece I found, that made this perfect boomy BANG."
Back in my workshop, I start developing a 808-ish Bassdrum. I started with the kick drum from my ex-drummers drum set (he hated me for trying to replace him with a robot!) and a mechanic beater. It didn't sound like a 808 at all. Hmm. I could also use a string from an old E-bass. Dampend. That sounded much more like a 808 bassdrum! Because - see above - a string frequency is much closer to a sine wave + envelope than a drum.
Last thing I tried was replacing the string with a metal tongue - as in a kalimba. To really get a deep bass sound I experimented with piezo contact mics and found out that you can get a decent clean bassdrum sound out of that. Its tuneble and has a nice decay. BOOM! Here we go!