Diatonik

Diatonik, also called diatonic in English, refers to the system of seven-note pitch collections and scales that underpin much of Western tonal music. It describes a set of seven distinct pitch classes within an octave, arranged in steps of whole and half tones. The most familiar members are the major scale and the natural minor scale, which follow the characteristic patterns of whole and half steps: major is W-W-H-W-W-W-H, natural minor is W-H-W-W-H-W-W. The term also encompasses the seven diatonic modes derived from the same pitch collection: Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, and Locrian.

In diatonic harmony, chords are built by stacking thirds on each degree of a diatonic scale, producing a set of triads and seventh chords such as I, ii, iii, IV, V, vi, and vii°. These diatonic chords form the functional backbone of tonal music, defining relationships of tension and resolution through tonic, subdominant, and dominant progressions. The concept of diatonic harmony distinguishes itself from chromatic harmony, which uses additional notes outside the diatonic set, and from modal mixture that borrows chords from outside the key.

Historically, the diatonic system has roots in ancient and medieval theory and was developed and codified during the Renaissance and the common-practice period. The term emphasizes a scale-based approach to melody and harmony, in contrast to systems that rely on non-diatonic pitch collections. The word derives from Greek through Latin, roughly meaning “through tones.”

Today, diatonic concepts remain central to music theory analysis, composition, and pedagogy, even as composers incorporate chromatic and non-diatonic elements.