diatonische

Diatonic refers to the diatonic scale and related musical material in Western tonal music. It denotes a set of seven pitch classes within an octave that forms the basis of major and natural minor scales, and of the modes derived from them. In practical terms, diatonic notes are the ones found in a given key signature, though occasional chromatic passing tones may appear.

The diatonic scale is defined by a pattern of whole and half steps; the most familiar example is the major scale (Ionian) with the interval sequence tone-tone-semitone-tone-tone-tone-semitone. The natural minor corresponds to the Aeolian mode with a different pattern. Other diatonic modes—Dorian, Phrygian, Lydian, Mixolydian, Aeolian, Locrian—share the same seven pitch classes.

In harmony, diatonic refers to chords built exclusively from notes of the diatonic scale. Triads on successive scale degrees form the diatonic family: I, ii, iii, IV, V, vi, and vii°, these chords underpin common-practice tonality, cadence, and functional harmony such as tonic, subdominant, and dominant relationships. Diatonic harmony tends to avoid introducing external pitch classes, though chromatic alteration exists within the key.

Historical context: The diatonic system underpins much Western music from the Renaissance through the Classical period. While the rise of chromaticism, modulation, and later atonality expanded options, the diatonic framework remains a core reference for analysis, pedagogy, and repertoire. In German-language theory, the adjective diatonische (or diatonisch) describes materials pertaining to the diatonic scale.