MICROTONAL MUSIC

music using tones that are not an exact number of semitones (half steps) apart. The smallest interval between two keys on a piano (e.g., between B and C, F and F, A and A) is the semitone, an interval also measured as 100 cents. There are thus 12 equal semitones, or 1,200 cents, to the octave. Much of the world's music, however, of both past and present times, uses intervals greater or smaller than 100 cents. In music not derived from the western European artistic traditions of the past 300 years or so, microtonal intervals often result from the use of tones that, in intonation, are close to the tones of the natural harmonic series (a sequence of overtones faintly audible above a fundamental note), an intonation not found in the tones of the piano. The Hindu scale divides the octave into 22 intervals, and most East Asian music has a tonal vocabulary of 12 tones generated in a cycle of fifths. Some Western composers and music theorists have assumed as a starting point the octave as divided into 12 equal semitones of 100 cents each and have suggested the use of microtonal intervals derived from ite.g., intervals of a quarter tone (50 cents), sixth tone (33.3 cents), 12th tone (16.7 cents), and 16th tone (12.5 cents). In this last case, the octave would consist of 96 equal divisions, and the modern semitone would equal eight of them in sequence; e.g., between B and C would lie eight equal 16th-tone intervals. Even in Western music, microtonal intervals of one sort or another appear to have been used at least from the time of the ancient Greeks onward; many theorists of the past have written about microtonal music in either observing musical practices of their time or making speculative suggestions for composers to take up. Among the better-known modern composers of microtonal music are Charles Ives, Harry Partch, Julin Carrillo, Alois Hba, and Krzysztof Penderecki.