IVOR DARREG, OCTOBER 1982

CHART OF THE JUST INTERVALS SHOWN BY THE FRET-LINES OF THE MEGALYRA FAMILY OF INSTRUMENTS.

Instruments bearing the above design have been exhibited in several art galleries, including LAICA, P.S.1, San Bernardino College, and elsewhere. Besides the lines for those just pitches stated above, all the instruments bear a parallel set of 12-tone equal temperament fret-Lines, usually colored green. The colors of a given line depend on the background color of the ldnstrument's board. For instance, if the board is green, gray lines may be used instead of green lines; if the instrument is blue, the blue lines can be replaced by light-gray or purple; if the instrument is red, orange lines may replace the red ones,. &c.

The number of just pitches actually shown on the board by colored lines, usually 19 per octave, is not enough to take care of the just pitches required for playing 6rdinary music in just intonation, but the instrumentalist, seeing how far certain actually-existing lines are from others, can move the steel bar a corresponding distance from some existing line to get a just' pitch separated by the same interval. For example the spacing for B-sharp from C can be inferred from the spacing of A-sharp from B-flat, or the spacing of a comma for a pitch a comma apart such as the two D's or the two A's. If any more lines were on the board, the background color could not be seen. Also it would destroy the appearance of the whole instrument as an abstract sculpture. The steel-guitar idea embodied in the Megalyra family of instruments does not admit of real precision, so small intervals such as that between A# two commas down and the seventh harmonic would be too small to show, since the lines on such large instruments must be wide enough to be easily visible; therefore in this case they would overlap considerably.

By placing both conventional 12-tone fret-lines and the above just fret-lines on the same board, it becomes a Comparison Chart showing the distortion created by the 12-tone temperament. Also it permits conventionally-trained musicians to play the instrument in ordinary ensembles.

From the 12-tone lines, quartertones can be easily estimated.