For most of 1985, my favourite song was Del Shannon's 1961 hit “Runaway”. So for over twenty years I've been puzzling over the question what the hell is that instrument from the break in the middle of the song?
It sounds like a synth, but that can't be right; this was 1961.
It turns out that yeah, it is a synthesizer, homemade by keyboardist Max Crook, which he calls the “musitron”.
Max developed the Musitron out of a variety of musical instruments and other electronic and electric devices. The initial keyboard is a clavioline, a french organ developed by Constant Martin in 1947. The clavioline is very similar in sound to that of the ondioline, developed by Georges Jenny, also of France. Crook created the Musitron by incorporating the majority of the clavioline, but being an electronics genius, Max was able to further enhance the clavioline by expanding the octave range to infinity (beyond human hearing). He inserted extra resistors, pots, and capacitors. The clavioline also lacked reverb. It was a dry sounding monophonic organ. Crook developed a spring echo reverberation unit custom-built from garden gate springs and other mechanical parts to create an echo chamber which, though crude, produced an amazing and natural echo sound resembing the acoustics of a tile-plated bathroom.
Even without the mystery, I still love the song.