I spotted this cool Sears Musical Piano Tomy toy on Ebay and thought, yes, Lady Penelope.
For some reason i though the Barbie doll and the piano reminded me of something with the Lady in Thunderbirds.
I'd love to see the Fairylite Lady P toy doll sat here.
Alas I couldn't find the puppet TV Penelope teasing the keys but I did find a couple of Thunderbirds piano shots from the episode, The Cham Cham. Are there more pianos in the series? Does the Lady actually play?