The ritsu and ryo scales are anhemitonic pentatonic scales -- five-note scales without semitones -- used in a type of Japanese Buddhist chant called shōmyō. The ritsu scale is built up by intervals of major second, minor third, major second, major second, minor third, while the ryo scale is major second, major second, minor third, major second, minor third. A third scale called Hanryo hanritsu is created by combining the ritsu and ryo scales however there is no agreed way to combine the two.