Tertian in the context of "Factor (chord)"

In the music theory of harmony, the root is a specific note that names and typifies a given chord. Chords are often spoken about in terms of their root, their quality, and their extensions. When a chord is named without reference to quality, it is assumed to be major—for example, a "C chord" refers to a C major triad, containing the notes C, E, and G. In a given harmonic context, the root of a chord need not be in the bass position, as chords may be inverted while retaining the same name, and therefore the same root.

In tertian harmonic theory, wherein chords can be considered stacks of third intervals (e.g. in common practice tonality), the root of a chord is the note on which the subsequent thirds are stacked. For instance, the root of a triad such as E Minor is E, independently of the vertical order in which the three notes (E, G and B) are presented. A triad can be in three possible positions, a "root position" with the root in the bass (i.e., with the root as the lowest note, thus E, G, B or E, B, G from lowest to highest notes), a first inversion, e.g. G, B, E or G, E, B (i.e., with the note which is a third interval above the root, G, as the lowest note) and a second inversion, e.g. B, E, G or B, G, E, in which the note that is a fifth interval above the root (B) is the lowest note.

An added tone chord, or added note chord, is a non-tertian chord composed of a triad and an extra "added" note. Any tone that is not a seventh factor is commonly categorized as an added tone. It can be outside the tertian sequence of ascending thirds from the root, such as the added sixth or fourth, or it can be in a chord that doesn't consist of a continuous stack of thirds, such as the added thirteenth (six thirds from the root, but the chord doesn't have the previous tertian notes – the seventh, ninth or eleventh). The concept of added tones is convenient in that all notes may be related to familiar chords.

Inversions of added tone chords where the added tone is the bass note are usually simply notated as slash chords instead of added-tone chords. For example, instead of C/D, just C/D is used.

In music or music theory, a thirteenth is the note thirteen scale degrees from the root of a chord and also the interval between the root and the thirteenth. The thirteenth is most commonly major Play or minor Play.

A thirteenth chord is the stacking of six (major or minor) thirds, the last being above the 11th of an eleventh chord. Thus a thirteenth chord is a tertian (built from thirds) chord containing the interval of a thirteenth, and is an extended chord if it includes the ninth and/or the eleventh. "The jazzy thirteenth is a very versatile chord and is used in many genres." Since 13th chords tend to become unclear or confused with other chords when inverted, they are generally found in root position. For example, depending on voicing, a major triad with an added major sixth is usually called a sixth chord Play, because the sixth serves as a substitution for the major seventh, thus considered a chord tone in such context.

In music theory, an eleventh chord is a chord that contains the tertian extension of the eleventh. Typically found in jazz, an eleventh chord also usually includes the seventh and ninth, and elements of the basic triad structure. Variants include the dominant eleventh (C, C–E–G–B♭–D–F), minor eleventh (Cm, C–E♭–G–B♭–D–F), and major eleventh chord (Cmaj, C–E–G–B–D–F). Using an augmented eleventh produces the dominant sharp eleventh (C, C–E–G–B♭–D–F♯) and major ninth sharp eleventh (Cmaj, C–E–G–B–D–F♯) chords.

A perfect eleventh creates a highly dissonant minor ninth interval with the major third of major and dominant chords. To reduce this dissonance the third is often omitted (such as for example in the dominant eleventh chord that can be heard 52 seconds into the song "Sun King" on The Beatles' Abbey Road album), turning the chord into a suspended ninth chord (e.g. C, C–G–B♭–D–F), which can be also notated as Gm/C.