History of multitrack recording

Multitrack recording of sound is the process in which sound and other electro-acoustic signals are captured on a recording medium such as magnetic tape, which is divided into two or more audio tracks that run parallel with each other. Because they are carried on the same medium, the tracks stay in perfect synchronization, while allowing multiple sound sources to be recorded at different times. The first system for creating stereophonic sound (using telephone technology) was demonstrated by Clément Ader in Paris in 1881. The pallophotophone, invented by Charles A. Hoxie and first demonstrated in 1922, recorded optically on 35 mm film. Some versions used a format of as many as twelve independent monaural tracks in parallel on each strip. Each track was recorded one at a time in separate passes and were not intended for later mixdown or stereophony due to the fact that each monophonic program was unrelated to the next - any more than one random album would be related to the next. Unlike with later half-track and quarter-track monophonic tape recording, the multiple tracks simply multiplied the maximum recording time possible, greatly reducing cost and incredible bulk. Alan Blumlein, a British engineer at EMI, patented systems for recording stereophonic sound and surround sound on disc and film in 1933. The history of modern multitrack audio recording using magnetic tape began in 1943 with the invention of stereo tape recording, which divided the recording head into two tracks. In 1948, Chicago's Armour Research Foundation announced that its staffer, physicist Marvin Camras, had produced a three-channel machine with "three parallel magnetic tracks on the same tape." The next major development in multitrack recording came in the mid-1950s, when the Ampex corporation devised the concept of 8-track recording, using its "Sel-Sync" (Selective Synchronous) recording system, and sold the first such machine to musician Les Paul.