During accompaniment, or while playing a chord melody, or even during an improvised passage, passing chords help to provide contour and movement to an otherwise ordinary chord progression.

LEADING TONE DIMINISH APPROACH - ASCENDING

Leading Tones provide resolution like that of a V-I cadence, where the 3rd of the V chord resolves up a 1/2 step to the root of the I chord. Therefore, if you precede any chord with it’s V7, you then achieve a brief resolution. This will strengthen the presence of the following chord, even if it is not the I chord. This temporary V7 chord is known as a SECONDARY DOMINANT.

It is common to substitute a V7 chord with the viio7 chord of the same tonality, being that 3 out of 4 of their chord tones are common. For instance, the secondary dominant of Emi7 - B7 [B-D#-F#-A] can be substituted by it’s respective viio7 - D#o7[D#-F#-A-C]. The only difference is the 'B' in B7 is replaced with the 'C' of D#o7. Simply put, D#o7 in root position, is the same as B7(b9) 1st inversion without it’s root.

EXAMPLE #3.)

Sound all the diatonic chords of the G Major scale in ascending order.
Be sure to use uniform voicings for a more consistent texture.

EXAMPLE #4.) Diatonic progression

Precede each diatonic chord with it’s leading tone dim7 passing chord - each serving as a ‘Secondary Dominant’ substitute. (same as V7(b9) 1st inversion without root)

EXAMPLE #5.) Stepwise progression

EXAMPLE #6.) Back-Cycle of Fifths progression

Even in progressions that are not step wise, you may precede each chord with it’s leading tone dim.7
This will again add movement to the already existing progression.

DOMINANT TRITONE SUBSTITUTE APPROACH - DESCENDING

The TRITONE is a #4 interval (or b5) and is the exact middle point of an octave. The tritone of ‘C’ is ‘F#’ or vice versa... the tritone of ‘F#’ is ‘C’.

The same applies with chords moved in parallel: The tritone of C7 is F#7, or vise versa... the tritone of F#7 is C7.

EXAMPLE #7.)

[C7=C-(E)-G-(Bb)] --- [F#7=F#-(A#)-C#-(E)].

In C7, the 3rd is ‘E’ and the b7th is ‘Bb’, whereas with F#7, the 3rd is ‘A#(Bb)’ and the b7 is ‘E’.
The fact that C7 and F#7(or any two other dom.7 chords separated by a tritone, for that matter) share the same guide tones (3rd & 7th), makes them extremely good candidates for chordal substitutions. These substitutions are called TRITONE SUBSTITUTES.

First let’s sound all diatonic chords in the G Major scale in descending order

EXAMPLE #8.) Diatonic progression

Precede each diatonic chord with it’s Secondary Dominant Tritone Substitute (shares same but reversed guide tones as V7)

EXAMPLE #9.) Stepwise progression

EXAMPLE #10.) Back-Cycle progression

PARALLEL MOTION APPROACH - WORKS BOTH UP AND DOWN

Of course you can also take any chord and just move it up or down in a parallel manner with out any regard to secondary dominants or diminish leading tones, lending a different yet interesting effect.

EXAMPLE #11.)

Applying Parallel Motion approach - just sliding the Dmi7 chromatically up Emi7 then back down to Dmi7.
After a while you should try going up and down these passing chords in a more random manner, letting your ear guide you. Then eventually start applying these ideas over actual tunes, and in time I think you’ll start looking at comping not as merely a supportive role, but as a more active and engaging part of the musical equation.

Recommended Songs: Any Blues Tune
All The Things You Are
Stella By Starlight
Ain’t Misbehavin
Makin’ Whoopie
Blue Monk
Confirmation