In music, a closely related key is one sharing many common tones with an original key, as opposed to a distantly related key (or "close key" and "distant key"). In music harmony, such a key shares all, or all except one, pitches with a key with which it is being compared, and is adjacent to it on the circle of fifths and its relative majors or minors.
Such keys are the most commonly used destinations or transpositions in a modulation, because of their strong structural links with the home key. Distant keys may be reached sequentially through closely related keys by chain modulation, for example C to G to D or C to C minor to E♭ major. For example, "One principle that every composer of Haydn's day kept in mind was over-all unity of tonality. No piece dared wander too far from its tonic key, and no piece in a four-movement form dared to present a tonality not closely related to the key of the whole series."
Given a major key tonic (I), the related keys are:
- vi (submediant or relative minor): same key signature
- IV (subdominant): one less sharp (or one more flat) around circle of fifths
- V (dominant): one more sharp (or one less flat) around circle of fifths
- i (parallel minor): same tonic, different key signature
|Major||Relative Minor||Subdominant and dominants|
|C||Am||F, G, Dm, Em|
|G||Em||C, D, Am, Bm|
|D||Bm||G, A, Em, F♯m|
|A||F♯m||D, E, Bm, C♯m|
|E||C♯m||A, B, F♯m, G♯m|
|B||G♯m||E, F♯, C♯m, D♯m|
|F♯||D♯m||B, C♯, G♯m, A♯m|
|G♭||E♭m||C♭, D♭, A♭m, B♭m|
|D♭||B♭m||G♭, A♭, E♭m, Fm|
|A♭||Fm||D♭, E♭, B♭m, Cm|
|E♭||Cm||A♭, B♭, Fm, Gm|
|B♭||Gm||E♭, F, Cm, Dm|
|F||Dm||B♭, C, Gm, Am|
Another view of closely related is that there are six closely related keys, based on the tonic and the remaining triads of the diatonic scale, excluding the dissonant leading-tone diminished triad. Four of which differ by one accidental, one with the same key signature, and the parallel modal form. In the key of C major these would be: D minor, E minor, F major, G major, A minor, and C minor.
In modern music, the closeness of a relation between any two keys or sets of pitches may be determined by the number of tones they share in common, which allows one to consider modulations not occurring in standard major-minor tonality. For example, in music based on the pentatonic scale containing pitches C, D, E, G, and A, modulating a fifth higher gives the collection of pitches G, A, B, D, and E, having four of five tones in common. However, modulating up a tritone would produce F♯, G♯, A♯, C♯, D♯, which shares no common tones with the original scale. Thus the scale a fifth higher is very closely related, while the scale a tritone higher is not. Other modulations may be placed in order from closest to most distant depending upon the number of common tones.
Another view in modern music, notably in Bartók, a common tonic produces closely related keys, the other scales being the six other modes. This usage can be found in several of the Mikrokosmos piano pieces.
When modulation causes the new key to traverse the bottom of the circle of fifths this may give rise to a theoretical key, containing eight (or more) sharps or flats in its notated key signature; in such a case, notational conventions require re-casting the new section to its enharmonically equivalent key.
Famous quotes containing the words closely related, key, closely and/or related:
“As to the family, I have never understood how that fits in with the other idealsor, indeed, why it should be an ideal at all. A group of closely related persons living under one roof; it is a convenience, often a necessity, sometimes a pleasure, sometimes the reverse; but who first exalted it as admirable, an almost religious ideal?”
—Rose Macaulay (18811958)
“There are two kinds of timiditytimidity of mind, and timidity of the nerves; physical timidity, and moral timidity. Each is independent of the other. The body may be frightened and quake while the mind remains calm and bold, and vice versë. This is the key to many eccentricities of conduct. When both kinds meet in the same man he will be good for nothing all his life.”
—Honoré De Balzac (17991850)
“But his kiss was so sweet, and so closely he pressed,
That I languished and pined till I granted the rest.”
—John Gay (16851732)
“Gambling is closely related to theft, and lewdness to murder.”