Miniature PiezoPiano: A One Octave Wonder.
The PiezoPiano is a tiny musical instrument with just one octave's range on the keyboard, featuring eight buttons and eight piezo transducers. It is a single PCB device with an ATmega4809 and has eight-note polyphony. The device is available as a kit on Tindie and is assembled in a cute enclosure mimicking the shape of a real grand piano.