Modular music is produced by synthesizers composed of separate modules for different functions. The modules can be connected together by the user to create a patch. The outputs from the modules may include audio signals, analog control voltages, or digital signals for logic or timing conditions. The first modular synthesizer was developed in the late 1950s, when the introduction of the Moog synthesizer and the Buchla Modular Electronic Music System crop up in the same period. Today the modular models offer range of complete systems some of which have been used by the producer to create this breathtaking collection.