The COLUMBINE is a a metal percussion instrument using 23 pitches per octave in an expanded just intonation tuning system. It was designed and built by Gayle Young in 1977, and expanded in 1978.
Columbine uses a just intonation tuning system of 61 pitches within a range of almost three octaves. The prototype was first played publicly in January of 1978, in a concert featuring new works by Gayle Young for microtonal tuning systems. It can be played with percussion mallets as well as with bows, much like a vibraphone.
The tuning was done with a frequency counter and sine tone generator. After the 61 steel tubes were cut to the correct lengths they were mounted over a trough-shaped wooden resonator.
The instrument has a hardwood stand that can be quickly disassembled, easily fitting into a station wagon—or its flight case—for travel.
The tuning system has 23 pitches per octave; the interval sizes varying between 20 cents, 40 cents and 70 cents. The tuning is based on an expanded just intonation system, using frequency ratios, or fractions, to define pitches. As the ratios used have no prime numbers over five, the tuning is based on adding, subtracting and transposing the first five pitches of the overtone series.
The notation system assigns to each pitch a coloured shape, which is placed on a five-line staff in the position of its closest pitch in standard notation. Each of three colours, green, red and blue, represents a transposition of a 13-tone modal pitch set including major and minor thirds and sixths, seconds and sevenths. There are two pitches for each major second, as the ratios 9/8 and 10/9 were both included; these pitches are separated by 20 cents.