Ernő Lendvai (February 6, 1925 – January 31, 1993) was one of the first music theorists to write on the appearance of the golden section and Fibonacci series and how these are implemented in Bartók's music, he also formulated the axis system, acoustic scale and alpha chord, an octatonic scale is any which number note musical scale?
Octatonic scale An octatonic scale is any eight-note musical scale. The scale most often meant by this term is one in which the notes ascend in alternating intervals of a whole step and a half step, creating a symmetric scale. In classical theory, in contradistinction to jazz theory, this scale is commonly simply called the octatonic scale (or octatonic collection), although there are forty-two other non-enharmonically equivalent, non-transpositionally equivalent eight-tone sets possible.
Unfigured bass Unfigured bass, less commonly known as under-figured bass, is a kind of musical notation used during the Baroque music era in Western Classical music (ca. 1600–1750) in which a basso continuo performer playing a chordal instrument (e.g., harpsichord, organ, or lute) improvises a chordal accompaniment from a notated bass line which lacks the guidance of figures indicating which harmonies should be played above the bass note (see figured bass). Figured bass parts have numbers or accidentals below the bass line which indicate which intervals above the bass should be played in the chord. However, not all basso continuo parts from the Baroque period were figured.