diatoniseen

Diatoninen, or diatonic in music theory, describes scales, chords, and tonal systems built from a set of seven pitch classes within an octave. In the common-practice era this diatonic collection is used to construct major and natural minor scales and the modal framework historically associated with medieval and Renaissance music.

A diatonic scale consists of five whole steps and two half steps arranged in a specific order, producing the well-known major (Ionian) pattern W-W-H-W-W-W-H. The natural minor (Aeolian) has the pattern W-H-W-W-H-W-W. Other diatonic forms are the seven modes derived from the parent scale: Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, and Locrian.

Diatonic harmony uses chords built from successive degrees of the diatonic scale, such as I, ii, iii, IV, V, vi, and vii°. Functional progressions and cadences rely on these diatonic triads and seventh chords.

In contrast, chromatic harmony incorporates notes or chords outside the diatonic set, often through borrowed chords, alterations, or modulation.

Historically, the diatonic system underpins much of Western tonal music from the Renaissance through the Romantic era; it continues to form the basis of music education and analysis even when non-diatonic elements are present.

In Finnish linguistic usage, diatoniseen is the illative case form of the adjective diatoninen and appears in phrases such as diatoniseen järjestelmään to mean "into a diatonic system."