This is a great kind of thing for getting people into music. There's a piano in my local pub and when people say they "can't play piano" I'll play a 2-5-1 in C and tell them to hit any of the white notes. People love that they can make up their own tunes having never played before.
I was miserable for most of my piano lessons (I learned to sheet read well – I become a fairly adept piano-playing robot – but I never sort of "figured out" music more generally.) That said, one lesson my teacher played a basic blues chord progression and told me to hit anything on the blues G scale however I wanted. That was one of the most fun times I've had making music ever. Well, the only time that has been fun, actually.
