I've ventured into three axis camera gimbal design before along with motor control and PID tuning, but one of the coolest features that gets me every time is the fact that most brushless gimbal motors actually beep when the gyroscope and motor driver are in sync. That simple yet elegant beep is a reminder that yes, a brushless motor is indeed an electro-mechanical system that can act as a sudo-speaker with the right input.
Why not take 8-bit music, a big ol fan and a DC input waveform and make an undercover lab speaker? Tone generation is one of the deciding characteristics for the main microcontroller for this project, as my go-to atmega328 may not be able to generate both the correct PWM for the fan and a high enough bandwidth output waveform to create the appropriate tone generation for music, let alone store a converted mp3-to-waveform equivalent file. I am leaning toward a cortex m0 alternative, but I still need to thoroughly research the process of 8-bit music conversion to a tone waveform. I can imagine a script to automate this process is in order.