A unit used in music to describe the ratio in frequency between notes. The difference between two frequencies in millioctaves is equal to 1000 times the base-2 logarithm of the ratio between the two frequences. One millioctave equals exactly 1.2 cents [3] or about 0.30103 savart. If two notes differ by 1 millioctave, the ratio between their frequencies is 21/1000 or approximately 1.000 6934