The yo scale is a pentatonic scale used in much Japanese music including gagaku and shōmyō.Japanese Music, Cross-Cultural Communication: World Music, University of Wisconsin – Green Bay. It is similar to the Western dorian mode, but does not contain all notes. The yo scale is used specifically in folk songs and early popular songs and is contrasted with the in scale.Titon, Jeff Todd (1996). Worlds of Music: An Introduction to the Music of the World's Peoples, p.372. . The in scale is described as more 'dark' while the yo scale is described as 'bright' sounding.Chris Hiscock, Marian Metcalfe (1999). New Music Matters 11-14, p.49. .
It is defined by ascending intervals of two, three, two, two, and three semitones. An example yo scale, expressed in western pitch names, is: D - E - G - A - B. This is illustrated below.
The Ryūkyū scale appears to be derived from the yo scale with pitches raised.
More recent theory (1974). (Japanese Music: History and Theory), 76. Tokyo: National Theater of Japan. emphasizes that it is more useful in interpreting Japanese melody to view scales on the basis of "nuclear tones" located a fourth apart and containing notes between them, as in the min'yō scale used in folk music, and whose pitches are equivalent to the second mode of the yo scale:Titon (1996), 373.
In India's Carnatic music, this scale corresponds to Udayaravichandrika.
See also Japanese mode Japanese musical scales Hirajōshi scale
References
Further reading Hewitt, Michael. Musical Scales of the World. The Note Tree. 2013. .