Block chords and doubled melody are easily used in a melody line that has a swing feel and strengthen the melody so as to separate that melody from the rhythmic background. Block chording was used to a large extent by jazz bands and orchestras such as those led by Count Basie and Duke Ellington. The pianist George Shearing was an early master of this technique, and lent his name to the Shearing voicing. There are a variety of methods:
- Generic block chord describes those that simply follow the above rule.
- Double melody (Commonly called the "Shearing voicing") with an additional fifth part that doubles the melody an octave lower.
- Drop 2 (technically not a block chord) with the second voice from the top transposed one octave lower.
If the melody note is part of the chord, the harmony notes are also taken from the chord.
This is a good technique if the melody note is diatonic (and not chromatic) and uses diminished chords for the notes that are not part of the chord. If the melody note is considered a passing tone, the harmony is created either by a diminished chord or a chromatically shifted chord. Before creating the harmonies, the chords could be converted to 6th chords, but this is not a rule.
Examples
The following is an example of harmonization of a C major scale with block chords. This example uses three diminished chords on the D, F, and B notes and includes an additional diminished chord on G#. This creates a balance in the harmonization of this scale by using all four existing diminished chords.
This example demonstrates the ways in which a melody line (in F major) could be block chorded using each method.