The original vintage Mellotron M400, the first tape based “sampler” ever built!
The Mellotron is an electro-mechanical, replay keyboard originally developed and built in Birmingham, England, in 1963. It evolved from a similar instrument, the Chamberlin, but could be mass-produced more effectively.
The instrument is played by pressing its keys, each of which presses a length of magnetic tape against a capstan, drawing it across a playback head. Then as the key is released, the tape is retracted by a spring to its initial position. Different portions of the tape can be played to access different sounds.