Altered Chord
Altered chords are a type of chord modification in which one or more scale degrees in a standard chord are raised or lowered by a step. This alters the quality of the chord, often increasing the amount of tension it has, and can be used to add more complexity and color to a chord progression. Alterations are most commonly applied to the fifth or to an extension (such as the ninth or eleventh), and while any chord can be altered, they are most commonly found in V chords and secondary dominants.
For example, a V chord in the key of C major consists of the scale degrees 5, 7, and 2 (G, B, and D). An altered dominant chord might modify the fifth (D) by lowering it to D♭, creating a V(♭5), or raising it to D♯, creating a V(♯5). Similarly, extensions like the ninth (A) can be altered by being raised to A♯, creating a V(♯9) chord.
More than one alteration is possible, creating complex chords like V7(♯5♭9). A V7(♯5♭9) chord in C major, for instance, would contain G, B, D♯, and A♭.
Below is a normal G7:
Below is an altered G7(♯5):
These alterations introduce tension, as the modified chord tones create dissonances that seek resolution. Altered chords are especially common in jazz and blues, as well as in other genres that make use of more complex harmonies.
One common use of altered chords is in cadences from V7 to I, where the raised or lowered tones in the V7 chord resolve smoothly to scale tones in the I chord. For instance, a V7(♯5) in C major (G, B, D♯, F) naturally resolves to I (C, E, G) as the altered fifth (D♯) moves up to E, strengthening the resolution.
The song "You've Got a Friend in Me" from the movie Toy Story by Randy Newman is an example of a song that uses altered dominant chords to add richness and tension to its progressions.
Other songs that use altered chords
Click on the following songs to see their chords and melody in the TheoryTab database.
