This is a demonstration of the clavioline, a rare old analog synthesizer, featuring some old recordings where the clavioline was been utilized:

• Frank Chacksfield’s Tunesmiths – Little Red Monkey
• Del Shannon – Runaway
• Demonstration of sirredfox00’s clavioline. It’s the pure sound of the clavioline, its own Leslie-Sound and effects and its tube amp.
• Tornados – Telstar

Sound On Sound’s Gordon Reid described the clavioline like this:

Physically, the Clavioline comprised two parts: a keyboard unit, which also contained the sound generator and controls, and a combined power supply, valve amplifier and speaker cabinet that looked like nothing so much as a cheap public address system. A dedicated multi-pin cable connected the two together, carrying a considerable amount of power to the keyboard to heat the valves, as well as carrying the audio signal back to the amplifier/speaker.

Players could attach the keyboard to the underside of a piano keyboard using the supplied metal brackets, but had to position it carefully so that they could control its volume using the integral knee lever, while still being able to pedal the piano itself. Alternatively, for those who preferred not to mount the Clavioline under a piano, there were several stands manufactured to support it at a playable height. These ranged from a stylish collapsible tripod that seems to have hailed from the USA, to the wobbly Selmer stand pictured here.

Resources:

• The story of the clavioline at SOS
• Wikipedia on the clavioline