circle of fifths
Music theory term for the circular diagram showing relationships among the 12 tones of the chromatic scale, their key signatures, and associated major and minor keys.
Using the circle of fifths, you can quickly tell the number of sharps or flats in a key signature.
Compound of 五度 (ごど, 'fifth (interval)') + 圏 (けん, 'circle' or 'sphere'), a direct translation of the English term 'circle of fifths'.