The Chamberlin is an electro-mechanical keyboard instrument that was a precursor to the Mellotron. It was developed and patented by the American inventor Harry Chamberlin from 1949 to 1956, when the first model was introduced. There are several models and versions of the Chamberlin. While most are keyboard-based, there were also early drum machines produced and sold. Some of these drum patterns feature the work of Chamberlin's son Richard. Development Harry Chamberlin's idea for the instrument came from recording himself playing an organ, and conceiving its playback as entertainment. He designed the first Chamberlin instrument as early as 1949, intended as a home entertainment device for family sing-alongs, playing the big band standards of the day. The Chamberlin's use as a commercial instrument in rock (or rock and roll) music was not considered, as Harry Chamberlin disliked rock music and rock musicians. The Chamberlin has a piano-style keyboard. Underneath each key is a tape-playing mechanism. Each tape is prerecorded with various musical instruments or special effects. When the musician presses a key, a pressure pad pushes the tape against a tape head, and a pinch roller beneath the key pulls it forward into storage box (or onto a roller mechanism). The electric signal generated by the tape head is amplified and heard through a loudspeaker. When the player releases the key, the sound stops, and the tape rewinds by either metal spring rods (on the early Chamberlins) or by a return-roller mechanism (on the later M1 models). Each tape is only a few seconds long (eight seconds on many units). Harry Chamberlin converted a walk-in closet into a home studio and spent considerable time (usually from sunrise to sunset) experimenting with sounds. After modifying the acoustics in the studio, and also in other rooms in his house, the first Chamberlin recordings were made. All Chamberlin recordings were contracted and performed by members of the Lawrence Welk Orchestra throughout the 1950s. Welk was impressed with the idea of a tape playback instrument and offered to fund its manufacture if it was called a "Welk" machine. Chamberlin refused Welk's offer. Chamberlin used Neumann U 47 microphones to record the sounds. The sounds are characterized by a very clean output and heavy vibrato, which was customary of the music styles of the time. The Chamberlin sounds have little compression and possess dynamics true to the instruments recorded on the tapes (such as the