micro:bit keypad synth with detuning.
A quirky musical toy that detects and displays tilting while using such input to alter the pitch of the notes being played.
Arduino-based drum sequencer and drum machine.
Just tap a rhythm on its touch sensors and it will start looping the sequence right away.
LED runner with LDR and sound. Press the button to roll and release it to get a number.
Uses a 555 timer and a CD4017 decade counter.