A chord progression, 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 they as a whole become an entity in themselves as a section, movement, or any other hypothetical name for a piece that to the ear can become familiar because of the harmonic progression used. Chord progressions are central to most modern European_influenced music. They may also be referred to as harmonic progressions. Compare to a simultaneity succession.

Generally, successive chords in a chord progression share some notes. This provides harmonic continuity within the progression (see voice leading).

The most common chords 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.

In music of the common practice period generally only certain chord progressions are used and many of the progressions not used are not traditionally tonal.

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-orientated 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/non-tonic differentiation."

The chord sequence of The Beatles' "I Saw Her Standing There" derives from a tree with both subdominant and dominant branches.

Source

• Middleton, Richard (1990/2002). Studying Popular Music. Philadelphia: Open University Press. ISBN 0335152759.
  • Steedman (1984).

Further reading

• Arnold Schoenberg -- Harmonielehre. Universal Edition, 1911. Trans. by Roy Carter as Theory of Harmony. University of California Press, 1978
• Arnold Schoenberg -- Structural Functions of Harmony. Ernest Benn Limited, second (revised) edition, 1969. Ed. Leonard Stein.
• Walter Piston -- Harmony, 1969. ISBN 0393954803.
• Vincent Persichetti -- Twentieth Century Harmony: Creative Aspects and Practice, 1961. ISBN 0393095398.

External links

• Olav Torvund's Chord progressions for Guitar (http://www.torvund.net/guitar/progressions/index.asp) website