Harmony Music

In music, harmony considers the process by which the composition of individual sounds, or superpositions of sounds, is analysed by hearing. Usually, this means simultaneously occurring frequencies, pitches (tones, notes), or chords. The study of harmony involves chords and their construction and chord progressions and the principles of connection that govern them. Harmony is often said to refer to the “vertical” aspect of music, as distinguished from melodic line, or the “horizontal” aspect. Counterpoint, which refers to the relationship between melodic lines, and polyphony, which refers to the simultaneous sounding of separate independent voices, are thus sometimes distinguished from harmony. In popular and jazz harmony, chords are named by their root plus various terms and characters indicating their qualities. In many types of music, notably baroque, romantic, modern, and jazz, chords are often augmented with “tensions”. A tension is an additional chord member that creates a relatively dissonant interval in relation to the bass. Typically, in the classical common practice period a dissonant chord (chord with tension) “resolves” to a consonant chord. Harmonization usually sounds pleasant to the ear when there is a balance between the consonant and dissonant sounds. In simple words, that occurs when there is a balance between “tense” and “relaxed” moments.

Some traditions of Western music performance, composition, and theory have specific rules of harmony. These rules are often described as based on natural properties such as Pythagorean tuning’s law whole number ratios (“harmoniousness” being inherent in the ratios either perceptually or in themselves) or harmonics and resonances (“harmoniousness” being inherent in the quality of sound), with the allowable pitches and harmonies gaining their beauty or simplicity from their closeness to those properties. This model provides that the minor seventh and (major) ninth are not dissonant (i.e., are consonant). While Pythagorean ratios can provide a rough approximation of perceptual harmonicity, they cannot account for cultural factors.

Early Western religious music often features parallel perfect intervals; these intervals would preserve the clarity of the original plainsong. These works were created and performed in cathedrals, and made use of the resonant modes of their respective cathedrals to create harmonies. As polyphony developed, however, the use of parallel intervals was slowly replaced by the English style of consonance that used thirds and sixths. The English style was considered to have a sweeter sound, and was better suited to polyphony in that it offered greater linear flexibility in part-writing. Early music also forbade usage of the tritone, due to its dissonance, and composers often went to considerable lengths, via musica ficta, to avoid using it. In the newer triadic harmonic system, however, the tritone became permissible, as the standardization of functional dissonance made its use in dominant chords desirable. Most harmony comes from two or more notes sounding simultaneously—but a work can imply harmony with only one melodic line by using arpeggios or hocket. Many pieces from the baroque period for solo string instruments—such as Bach’s Sonatas and partitas for solo violin and cello—convey subtle harmony through inference rather than full chordal structures. These works create a sense of harmonies by using arpeggiated chords and implied basslines. The implied basslines are created with low notes of short duration that many listeners perceive as being the bass note of a chord.