Hum

it cannot sound wrong.

a chord that keeps evolving — tap to add a voice, drag to tune it

Every pitch offered here belongs to one pentatonic scale, so no combination of taps and drags can land on a discordant interval — the harmony is guaranteed by which notes exist to begin with, not by anything you have to avoid. Left alone it keeps singing on its own; touched, it only adds another voice to what’s already going.

Concepts: harmony, sound.

An interactive you play with one thumb, on Wundr.