The Dubreq Stylophone, a miniature electronic musical instrument, invented in 1967 by one Brian Jarvis, consisted of a metal keyboard that was played by touching it with a stylus.
David Bowie used a Stylophone on his 1969 hit Space Oddity and Rolf Harris advertised them.
How exciting! A great deal of fuss has been made of the Stylophone on 1970s nostalgia shows and websites (70s? It was actually first available in the 60s!) but that, in my opinion, simply shows desperation to glitz the 70s up.
The only person I ever knew that owned a stylophone was my dear old gran, who had just got rid of her piano to make more space.
Sadly, she found the Stylophone no substitute.