noun
diatonic scale
Music term for the seven-note scale pattern of whole and half steps, as opposed to the chromatic scale (半音階).
See also: 半音階
全音階は、ピアノの白鍵だけで演奏できる音階です。
The diatonic scale is a scale that can be played using only the white keys of a piano.
半音階 is the chromatic scale (all twelve semitones), while 全音階 is the diatonic scale (seven notes with whole and half steps).
Compound of 全 (zen, 'whole') + 音階 (onkai, 'musical scale'), referring to a scale built primarily from whole steps.