Monday, June 8, 2015

Kinds of Harmonies

Harmony makes it possible to gain an appreciation for all types of music. Harmony creates context and a foundation for melodies by providing movement and color to support melodic ideas. There are several ways to create harmony, and each kind of harmony has its own specific purpose. Learning about the different types of harmonies makes it easier to identify harmony in context.

Intervals


Intervals are two independent sounds performed at the same time. This type of harmony makes it possible to create richer textures by juxtaposing two melodies and is the basis for counterpoint. Gregorian chant often consists of simple, two-note harmonies, and this kind of harmonization must be used cautiously to avoid parallel motion, or both lines moving in the same direction at the same time. When both lines move together, it gives the impression that both lines are actually just one line. To prevent this, composers make each line move in an opposite direction (oblique motion) or contrary to each other (contrary motion.)

Triads


Triads consist of a series of three notes played simultaneously. Triads are usually built with a bass note called the root, an interval of a third above that and a fifth above the root. Triads create harmony when performed, and they create chord progressions or successions when played consecutively. For instance, when a series of chords changes from one triad to another towards a goal, if at least one note stays the same, you have a chord progression. If the triads move randomly without a goal, they are chord successions. Basic types of triads include major, minor, augmented and diminished.

Seventh Chords


Seventh chords are triads with a root, third and fifth, but they also have a seventh added to the top of the chord. These chords typically help create resolutions in harmonies since the seventh typically "wants" to resolve. This resolution creates a strong pull between chords and helps to create a sense of finality in a composition. Seventh chords include major-minor sevenths, major sevenths, fully diminished sevenths, half-diminished sevenths and minor sevenths. The type of seventh chord is determined based on the triad quality and the interval of the seventh in relationship to the bass.

Extended Harmonies


In addition to traditional harmonies, there are also extended harmonies. Harmonies created by stacking fourths, as in much of Aaron Copland's music or harmonies created by fifths are common in modern music. Tone clusters are several notes without a traditional relationship to each other. Additional methods include using scales like the whole-tone scale, octatonic and pentatonic to create chords that are common in modern music.