With help from her skipping rope, Alma Deutscher has written an opera that's being staged this Christmas in Vienna, the capital of classical music. Not bad when you're aged 11 and three-quarters.
"I sometimes think that if I had a beard and I was old and fat then people might take me a bit more seriously," the English "wunderkind" said as she played on the piano excerpts of the work.
But this attitude, she adds, has changed since preparations began in this hallowed former stamping ground of Mozart and Schubert for the December 29 premiere of "Cinderella".
She started writing the two-hour opera when she was eight, and as well as composing the music she has given the traditional folk tale her own twist, setting it in an opera house.
She has won praise from renowned conductors like Daniel Barenboim and a "bowled over" Simon Rattle. Last year she appeared at a Google Zeitgeist conference with the likes of Stephen Hawking.
But, her dad says, Alma also has a very normal life. "She loves climbing trees and running around like every other child," he said.
Modern music though is "too loud" and not her thing, she says -- not even Justin Bieber or The Beatles. "Oh no, I don't know any of them!"