An alternative to VCOs in creating basic signal waveforms, commonly used in electric organs and pianos but less frequently in synthesizers. The basic top-octave division setup uses a set of 12 oscillators (which may or may not be voltage controlled), one for each note in the chromatic scale, and in the highest octave that the instrument is capable of playing. Octave dividers are then used to create the chromatic scales for each of the lower octaves; each time that one of the top octave notes is divided by 2 (halving its frequency), it creates that note one octave lower. This is distinct from a divide-down architecture, which uses a single ultrasonic master oscillator.