The in scale begins to be common in Japanese folk songs and music.

The in scale (also known as the Sakura pentatonic scale due to its use in the well-known folk song Sakura Sakura) is, according to a traditional theory, one of two pentatonic scales used in much Japanese music, excluding gagaku and Buddhist chanting.

The in scale, which contains semitones, is used specifically in music for the koto and shamisen and is contrasted with the yo scale, which does not contain semitones.