* Genesis of a Music* is a book first published in 1949 by microtonal composer Harry Partch (1901–1974).

Partch first presents a polemic against both equal temperament and the long history of stagnation in the teaching of music; according to Alex Ross, this is "the most startling forty-five-page history of music ever written". In particular, Partch holds Johann Sebastian Bach responsible for "the movement toward equal-tempered tuning, which meant that composers could not absorb the scales of other world traditions; and the urge to make music ever more instrumental and abstract."^{[1]}

He then goes on to explain his tuning theory based on just intonation, the ensemble of musical instruments of his own invention (such as the "Surrogate Kithara, a struck-string, harplike instrument",^{[2]} and the guitar with movable frets he used to compose *Barstow*^{[3]}), and several of his largest musical compositions.

The book has been highly influential to succeeding generations of microtonal composers, including Lou Harrison,^{[4]} Ben Johnston,^{[5]} and James Tenney.^{[6]} A revised and enlarged second edition was published just before Partch's death in 1974.^{[7]}

Partch presents 4 "basic monophonic concepts":

- Consonance and dissonance: "The ear informs us that tones which are in small-number proportion, say in the relation of 2 to 1, are strong, clear, powerful, consonant."
^{[8]}- "The smaller the number involved in the [interval] ratios, the more consonant the ratio; the larger the numbers, the more dissonant".
^{[9]}

- "The smaller the number involved in the [interval] ratios, the more consonant the ratio; the larger the numbers, the more dissonant".
- "Dual Identity": "Every ratio of a Monophonic system is at least a dual identity."
^{[8]}- "Odentity [is] determined by the odd-number ratio component of the numerator, and another one, the Udentity [is] determined by the odd-number component of the denominator. A ratio thus always belongs to two tonalities, an Otonality in accordance with its Odentity, and an Utonality in accordance with its Udentity."
^{[9]}

- "Odentity [is] determined by the odd-number ratio component of the numerator, and another one, the Udentity [is] determined by the odd-number component of the denominator. A ratio thus always belongs to two tonalities, an Otonality in accordance with its Odentity, and an Utonality in accordance with its Udentity."
- Minor: "Under-number Tonality, or Utonality ("minor"), is the immutable faculty of ratios, which in turn represent an immutable faculty of the human ear."
^{[8]}- See: Arithmetic progression and Undertone series

- History: Music has appeared to have advanced up the harmonic series throughout history.
^{[8]}- Pythagorean tuning is 3-limit, "just intonation" often refers to 5-limit tuning, while Partch uses an 11-limit tuning. Partch admirer Ben Johnston uses 31-limit or higher "extended just intonation". See: Emancipation of the dissonance

*Genesis of a Music: Monophony: the relation of its music to historic and contemporary trends; its philosophy, concepts, and principles; its relation to ... and its application to musical instruments*, University of Wisconsin Press, 362 pp., 1949. ASIN B0007DM7I8*Genesis Of A Music: An Account Of A Creative Work, Its Roots, And Its Fulfillments*, Second Edition, Da Capo Press, Paperback, 544 pp., 1979. ISBN 0-306-80106-X. 2009: ISBN 9780786751006.