The synthesizer makes use of two polyphonic modes and two monophonic modes. Popular monophonic synthesizers include the Moog Minimoog. It was recorded entirely with a Korg monophonic synthesizer. Instruments that are not capable of polyphony are monophonic or paraphonic. It combined a calculator, a monophonic synthesizer, and sequencer. In synthesizers legato is a type of monophonic operation. He also started playing the monophonic synthesizer. All other characters sing in monophonic plainchant. The earliest innovations upon monophonic plainchant were heterophonic. The Gregorian chant was known for its very monophonic sound. The tunes were primarily monophonic (a single melody without accompaniment) and transmitted by oral tradition. Both were portable, analog, monophonic, and relatively compact. The best-known examples of Middle Ages music notation are medieval manuscripts of monophonic chant. Attribution of monophonic music of the medieval period is not always reliable. Music in the Ethiopian highlands is generally monophonic or heterophonic.