Harmonies

Harmony in music refers to the simultaneous sounding of pitches and the system that governs their relationships. It encompasses chords—three or more notes sounded together—and the ways those chords relate to one another as a sequence within a piece. Harmony provides vertical structure that supports the melody and form.

Harmonic practice centers on chords, intervals, and voice leading. Triads (major and minor, plus diminished and augmented variants) form the basic building blocks; seventh chords add further color. The arrangement of chords in progressions creates movement, tension, and release as consonance and dissonance resolve.

In Western tonal music, functional harmony describes how chords relate to a tonic center. Chords assume roles such as tonic, predominant, and dominant, guiding root movement and shaping cadences that mark phrases. Modulation can shift the tonal center to related keys, expanding harmonic range.

Historically, harmony developed from modal writing and early polyphony to the tonal systems of the common-practice period (roughly 1650–1900). The Romantic era broadened harmony with chromaticism and extended chords. The 20th century introduced new approaches, including atonality, polytonality, and nonfunctional or alternative harmonic systems in various traditions.

Harmony is analyzed with systems such as roman numeral notation and figured bass to indicate scale-degree functions and chord inversions. Composers vary approaches to texture and color—such as parallel harmony, counterpoint with harmonic context, and spectral or modal sonorities—to shape mood and musical architecture.