After a concert at Carnegie Hall in 1975, Rick Wakeman (Yes's keyboard player) met David Biro, who lived in Connecticut. Biro showed him his invention : an instrument that could play recorded sounds without the downsides of a Mellotron (sounds limited to 8 seconds, impossibility to play fast... ). It was a keyboard connected to twenty 8 track cartridge readers (the same kind of cartridge that was used in auto radios in the seventies, especially in the USA). These cartridges had looped tapes, and didn't need to rewind.
Seduced by the prototype, Rick Wakeman created Birotronics with Peter Robinson. This company was based in England, and its purpose was the production of Birotrons. The price of the machine was £1000, and over 1000 orders were taken.
However, the Birotron came too late. The end of the seventies was the time when the first polyphonic synthesizers (Polymoog, Prophet V... ) and the first samplers (Fairlight... ) appeared ; thus, it wasn't long before the Birotron was obsolete. 13 machines were made, and Birotronics went bankrupt in 1979. Today, there are only 5 ou 6 Birotrons left in the world.
One single model was made from 1975 to 1978 : the Birotron B90.
It had a 37 note keyboard, and nineteen cards with nineteen 8 track cartridge readers. Each card was allotted 2 keys on the keyboard, and each card had 2 preamps, 2 envelope generators and 2 VCA.
4 sounds were recorded on each tape. The available sounds were : violins, strings, cello, organ, male choir, brass section, wind ensemble, flute, recorder.
Rick Wakeman owned 4 Birotrons. Two of them disappeared, and the other two were accidentally damaged during tours. The Birotron can be found on two Yes albums, Tormato and Yesshows, and also on Wakeman's solo album, Criminal Record.
Tangerine Dream and Earthstar are the only other famous bands who have used a Birotron.
On The Silent Wings Of Freedom You Can Be Saved (bonus track)