The ascent of the scale.
The ascent is expressed as a series of integers, each giving a semitone distance above the tonic. It must have at least two elements, start at zero (the tonic), be monotonically increasing, and stay below 12 (the next tonic above).
The number of elements in the ascent tells us how many notes-per-octave in the scale. For example, a heptatonic scale will always have seven elements in the ascent.
ScalePattern Class | Midi Namespace