The Radiotone was a device, apparently of French origin, fitted by Christies to their Electric, Bournemouth installation.
According to Whitworth in his book “The Cinema and Theatre Organ”, it consisted of a string bowed by a circular wheel with a series of electro-mechanically-operated fingers to stop the string for different notes. The vibrations of the string were picked up, amplified thermionically and fed to loudspeakers in the theatre. Different tone colours could be obtained, and Whitworth notes that at maximum volume, the Radiotone could be accompanied by the full organ. It seems, therefore, to have had much in common with Compton’s Solo Cello .
Sir Dan Godfrey is reported to have said, “Radiotone is a wonderful invention with great possibilities”. No further examples are known of Radiotone being fitted to theatre organs.