Which composer played on a special piano so he could alter the key he was playing on with a lever? What was his favorite key?

( BTW, it is also my favorite key to play on).

Israel Balinin (?) born in Russia, who became Irving Berlin after immigrating, was a composer who never quite got the hang of a keyboard. If you write Alexander's Ragtime Band and White Christmas you can afford the indulgence He certainly had a special piano made so he could change key by use of a lever.The key he preferred would have to be F sharp. There's a story that someone asked him what knowing and understanding keys would have done to his music career. He replied " Ruin it!".

It was the key where I have learn to play by ear at 5 years old . F sharp key. Still is my favorite.

Good answer Fred, Source look under "other types"
Irving Berlin