Hirajoshi
2 - 1 - 4 - 1 - 4About Hirajoshi
Hirajoshi is 1 2 b3 5 b6 — a Japanese pentatonic with two half steps and two minor thirds, and no fourth or seventh. Strictly it is the name of a koto tuning rather than a scale, and the difference matters: the instrument is tuned to these pitches, and the melodic practice follows from that.
A tuning that became a scale name
Hirajoshi is the standard tuning of the koto, in which the thirteen strings are set to these five pitch classes across three octaves. Western sources list it among scales because that is the shape a Western listener extracts from the repertoire, but in its own system it names how the instrument is strung.
This explains an oddity in the sources: the intervals attributed to hirajoshi differ between references, because different rotations of the tuning are transcribed as the scale. The set of pitch classes is stable; where a Western author decides the root lies is not.
Two half steps, two leaps
The structure is a whole tone, a half step, a minor third, a half step, a minor third. Each half step is followed by a leap, and that alternation is the sound: a step that tightens, then a gap that opens. Melodies in this material rarely walk, they arrive.
The scale has no fourth and no seventh. Against a Western ear expecting either, the gaps read as omissions, and the resulting melodies feel elliptical rather than incomplete once the pattern is heard a few times.
How it is used
In koto and shamisen repertoire it is the default material of a whole tradition. Outside it, it is the first choice for anything meant to signal Japan, to the point of cliché — five notes over a sustained bass has stood in for an entire musical culture in scores for decades.
Used as harmony rather than signal, it sits over minor chords with a flat sixth and over sus chords, and it makes a strong ostinato because the two minor thirds give it internal symmetry.
Confusions and neighbours
Hirajoshi is confused with in-sen, which has no third, and with iwato, which is a rotation of the same kind of material with a flat second and a flat fifth. It is also confused with itself: sources disagree about its rotation, so two references can give different interval sets under one name.
Its neighbours in this family are iwato, in-sen and kumoi. Kumoi is the most useful comparison — it keeps the minor third but replaces the flat sixth with a natural sixth, and the darkness lifts entirely.
Frequently asked questions
What is the hirajoshi scale?
A Japanese pentatonic, 1 2 b3 5 b6. In C: C D E♭ G A♭.
Is it a scale or a tuning?
Originally a koto tuning, hirajoshi being the name of the tuning itself. Western sources treat the pitches as a scale.
Why do sources give different notes for it?
Because different rotations of the tuning are transcribed as the scale. The pitch classes agree; the assumed root does not.
Related Scales from Pentatonic
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