Here’s a BBC article about a musician who taught himself keyboards by playing on paper keys.
How I learned :
I experimented with string sounds when I was little by wrapping rubber bands around a cigar box. In my household my brother had the main musical instrument, a beautiful electric organ with 3 keyboards and full sets of pedals, he became a very accomplished church organist.
I started out experimenting with anything that made a sound then I borrowed a little guitar from a friend who bought it with green “saving stamps” (that was a grocery thing, you got “stamps” as you bought groceries and saved them in booklets you could trade for inexpensive items).
When I’d taught myself 3 songs on the cheap guitar my parents were so impressed that they took me down to a pawn shop and got me my first real guitar. I was in 12 year old heaven and it was a really nice Guild acoustic.
My Mom took me out to a pro shop to see about guitar lessons. The owner turned me away because he said my hands were too small. So, I went home and taught myself, playing with different string tunings and fingering patterns. I made up my own style and played six and twelve string guitars throughout my career.
The moral of this story ? NEVER LET ANYONE TELL YOU YOU CAN’T DO SOMETHING !