By Bruce Clarke
In a conventional jazz performance the following general format prevails:
Chorus 1. Statement of melody or harmonic chart.
Chorus 2 etc. Unspecified number of improvised choruses or solo sections.
Final Chorus. Restatement of melody plus coda or tag.
Obviously these repeated choruses must be joined by some smooth sequence of chords connecting the end of one chorus with the beginning of the next.
Most jazz tunes fall into the following structural categories:
- 32-bar form; melody closing on Bar 31 on Major I chord.
- 32-bar form; melody closing on Bar 32 on Major I chord.
- 32-bar form; melody closing on Bar 31 on minor I chord.
- 32-bar form; melody closing on Bar 32 on minor I chord.
- 64-bar form; melody closing on Bar 61 on Major I chord.
This means that in forms 1 and 3 a two-bar (bars 31 and 32) turnaround is required.
In forms 2 and 4 a one-bar (32nd bar) turnaround is required.
In form 5 a four-bar (bars 61, 62, 63 and 64) turnaround is required.
Rule: The final melodic tone indicates the beginning of the turnaround.
The problem now remains to determine the chords to be employed. Since, in any case, the turnaround begins on either the Major 1 or the minor I chord, the question remains to find the most suitable chords to connect this I chord to the first chord of the tune.
The following categories include the principal initial chords (not including pick-up beats):
- Tunes beginning on the I chord.
- Tunes beginning on the II chord.
- Tunes beginning on the VI chord.
When the tune begins on a less obvious chord, “cover” the turnaround by using a basic I-VI-II-V pattern, then proceed directly to the initial chord of the tune.
Rule: Turnaround patterns are determined harmonically by the initial chord and rhythmically by the closing bar of the melody.
From the preceding observations the following solutions are suggested:
A common turnaround device, employed to sustain tension while passing from one chorus to the next, is that of employing the fifth of the prevailing key (major to minor) in the bass while moving through a turnaround pattern in the right hand.
This device is known as an organ-point or pedal-point and may be joined with any basic pattern of the prevailing key: