Music Sound

A chord progression (also chord sequence and harmonic progression or sequence), as its name implies, is a series of chords played in an order. Part and parcel of this action is the idea that the chords relate to each other in some way, whether closely or distantly, and as a whole become an entity in themselves. Chord progressions are central to most modern European-influenced music and create cyclic or sectional musical forms. Compare to a simultaneity succession.

A chord change is a movement from one chord to another and may be thought of as either the most basic chord progression or as a portion of longer chord progressions which involve more than two chords. Generally, successive chords in a chord progression share some notes. This provides harmonic continuity within the progression.

The most common chord progressions in Western classical and pop music are based on the first, fourth, and fifth scale degrees (tonic, subdominant and dominant); see three chord song, eight bar blues, and twelve bar blues. The chord based on the second scale degree is used in the most common chord progression in Jazz, ii-V-I.

Chord progressions are usually associated with a scale and the notes of each chord are usually taken from that scale. Melodies and other parts usually comply with the chord changes in that their notes are usually taken from the chord currently playing. Notes which are not taken from the chord are called nonchord tones and usually resolve quickly to a chord tone.

The "circle progression" is generally regarded as the most common progression of the common practice period. A circle progression is a progression of descending perfect fifths, and derives its name from circle of fifths. Circle progressions, in practice, often occur in their inversion, an ascending perfect fourth. Circle progressions make up many of the most commonly used progressions, such as ii, V, I in major keys, and the strong pull of a circle progression is a large part of the reason the dominant chord (V - if functioning as a dominant chord will be a major triad or a dominant seventh chord, even in minor keys) "leads" to tonic (I, or i).

In music of the common practice period, generally only certain chord progressions are used. Many of the other unused progressions are not traditionally considered tonal. It should be noted, however, that in most styles of music, chord progressions are resultant from voice leading patterns; thus the preceding observations are merely generalizations.

Table of common progressions during the common practice period

Table of Common Progressions
I, i	May progress to any other triad. May interrupt any progression.
Major keys		Minor keys
ii	ii-V, ii-vii6�	ii6�	ii6�-V
		ii*	ii-V, ii-vii6�
iii	iii-ii6, iii-IV, iii-V, iii-vi	III	III-ii6�, III-iv, III-VI
IV	IV-I, IV-ii, IV-V, IV-vii6�	iv	iv-i, iv-ii6�, iv-V, iv-VII
		IV*	IV-V, IV-vii6�
V	V-I, V-vi	V	V-i, V-VI
		v*	v-VI
vi	vi-ii, vi-IV, vi-V, vi-iii-IV	VI	VI-ii6�, VI-iv, VI-V, VI-III-iv
vii6�	vii6�-I, VII6�-V	vii6�/VII	vii6�-i/VII-III
* ii and IV in minor used with an ascending #6; v in minor used with a descending 7. See the article chord (music) and chord symbol for an explanation of the notation used in this table.

Contents 1 Visual Table for the Rules for Common Chord progressions 2 Rewrite rules 3 References 4 External links

Visual Table for the Rules for Common Chord progressions

Rewrite rules

Steedman (1984) has proposed a set of recursive "rewrite rules" which generate all well-formed transformations of jazz, basic I-IV-I-V-I twelve bar blues chord sequences, and, slightly modified, non-twelve-bar blues I-IV-V sequences ("I Got Rhythm"). Important transformations include:

• replacement or substitution of a chord by its dominant or subdominant, example:

1 2  3 4   5  6   7    8    9  10 11 12
I/IV/I/I7//IV/VII7/III7/VI7//II7/V7/I/I//

• use of chromatic passing chords, example:

...7    8    9...
...III7/bIII7/II7...

• and chord alterations such as minor chords, diminished sevenths, etc.

Sequences by fourth, rather than fifth, include Jimi Hendrix's "Hey Joe":

1        2        3 4  5          6       7 8   9         10      11 12
bVi, bIII/bVII, IV/I/I//bVI, bIII/bVII, IV/I/I//bVI, bIII/bVII, IV/I/I//

These often result in Aeolian harmony and lack perfect cadences (V-I). Middleton (1990, p.198) suggests that both modal and fourth-oriented structures, rather than being "distortions or surface transformations of Schenker's favoured V-I kernel, it is more likely that both are branches of a deeper principle, that of tonic/not-tonic differentiation."

References

• Middleton, Richard (1990/2002). Studying Popular Music. Philadelphia: Open University Press. ISBN 0335152759.
  • Steedman M.J., "A Generative Grammar for Jazz Chord Sequences", Music Perception 2 (1) (1984) 52-77.

External links

• Olav Torvund's Chord progressions for Guitar website
• Guitarz Forever's Three Chord Progressions For Guitar website