Sointuharmonia

Sointuharmonia, Finnish for chord harmony, is a branch of music theory that studies how chords are formed and used to support and relate to melodies in tonal music. It explains the construction of triads and seventh chords from a scale and how these chords function within a key. The topic also covers diatonic harmony, chord progressions, and harmonic rhythm.

The core concepts include functional harmony, where chords are grouped into tonic, predominant, and dominant functions, and Roman numeral analysis (I, ii, iii, IV, V, vi, vii°). Voice leading and smooth part-writing are emphasized to create coherent textures. Common practice period conventions govern cadences, chord spacing, and the resolution of tensions. Harmonic extensions and alterations, such as ninths, elevenths, thirteenths, secondary dominants, and borrowed chords from parallel modes, expand the palette.

Applications: In composition and arrangement, sointuharmonia guides melodic support, tension-building, and color. Jazz and popular music adapt the framework with extended chords, substitutions, modal interchange, and non-functional progressions, while classical music often follows stricter functional patterns. Analyses of progressions and cadences help performers anticipate harmonic movement and musicianship.

This field intersects with voice leading, orchestration, and pedagogy, serving as a foundation for understanding repertoire from baroque to contemporary genres.