What is "subtonic"

Subtonic \Sub*ton"ic\, n.

1. (Phonetics) A subtonic sound or element; a vocal consonant, as b, d, g, n, etc.; a subvocal.

2. (Mus.) The seventh tone of the scale, or that immediately below the tonic; -- called also subsemitone.

Subtonic \Sub*ton"ic\, a. (Phonetics) Applied to, or distinguishing, a speech element consisting of tone, or proper vocal sound, not pure as in the vowels, but dimmed and otherwise modified by some kind of obstruction in the oral or the nasal passage, and in some cases with a mixture of breath sound; -- a term introduced by Dr. James Rush in 1833. See Guide to Pronunciation, [sect][sect]155, 199-202.

a. (context phonetics dated English) Of or pertaining to imperfectly articulated sounds or utterances that are inaudible or barely audible, as characterized by Dr. James Rush (''Guide to Pronunciation'', 1833). n. 1 (context music English) The note immediately below the upper note of a musical scale. 2 (context phonetics dated English) An imperfectly articulated sound or utterance, as characterized by Dr. James Rush (''Guide to Pronunciation'', 1833).

n. (music) the seventh note of the diatonic scale [syn: leading tone]

In music, the subtonic is the scale degree below the tonic or, more specifically, the flattened seventh (VII): the lowered or minor seventh degree of the scale, a whole step below the tonic, as opposed to the leading tone, which is only a half step below the tonic. The distinction between leading tone and subtonic has been made by theorists since at least the second quarter of the 20th century.

The subtonic appears in three forms: as the scale degree, $\hat 7$, melodically and as the chord VII in both VII-I cadence and in modulations harmonically. The word is also used as an English translation of subtonium, the Latin term used in Gregorian chant theory for the similar usage of a tone one whole step below the mode final in the Dorian, Phrygian, and Mixolydian modes.

For example, in the A minor scale (white keys on a piano, starting on A), the subtonic is the note G (in C major this would be B); and the subtonic triad consists of the notes G, B, and D (in C: B-D-F). In music theory, the subtonic chord is symbolized with the Roman numeral VII for a major triad built on the note, or vii for a minor triad; in a minor key, the flat symbol is sometimes omitted by some theorists because the subtonic note appears in the natural minor scale, but the flat symbol is usually used for the major scale because the subtonic is a non-scale note.

In jazz, the flattened seventh is also used as a substitute for the dominant, V, especially in the Backdoor cadence, ii-VII7-I, where the subtonic is used for the dominant seventh. VII is in this case a pivot chord borrowed from the parallel minor (its dominant seventh). V7 and VII7, the subtonic seventh chord, have two common tones, in C: GBDF and BDFA.

However, while, "the leading-tone/tonic relationship is axiomatic to the definition of common practice tonality," especially cadences and modulations, in popular music and rock a diatonic scalic leading tone (i.e., $\hat 7$-$\hat 1$) is often absent. In popular music, rather than "departures" or "aberrant," the "use of the 'flattened' diatonic seventh scale degree...should not even be viewed as departures ".