chordstriads

Chordstriads are chords consisting of three distinct pitch classes formed by stacking two third intervals above a root note. The three tones—the root, a third above, and a fifth above—form the triad's basic sonority. Triads derive their quality from the intervals between the root and the other two notes: major triad (root–major third–perfect fifth), minor triad (root–minor third–perfect fifth), diminished triad (root–minor third–diminished fifth), and augmented triad (root–major third–augmented fifth).

Inversions reorder the notes: root position (root–third–fifth), first inversion (third–fifth–root), second inversion (fifth–root–third). In tonal music, triads are typically built on each scale degree, yielding diatonic triads. For example, in C major the diatonic triads are C major (I), D minor (ii), E minor (iii), F major (IV), G major (V), A minor (vi), and B diminished (vii°). These triads establish functional harmony: tonic, predominant, and dominant roles guide progressions and voice leading back to the tonic.

Notational and analytical aspects: Triads are written with chord symbols such as C, Cm, Cdim, Caug; in Roman numeral analysis, I, ii, iii, IV, V, vi, vii°. While triads are the simplest chord type, they form the basis for more complex structures such as extended chords by adding notes beyond the triad.