“It’s just a passing chord.” bassists hear this slightly condescending explanation from guitarists and keyboard players who don’t want to bother clarifying what’s really happening in a chord progression. A passing chord is a general description for any chord outside of a diatonic key center, often connecting two chords that naturally occur in the key signature or key center.
Last month, we looked at 12-tone rows, which use all 12 notes of the chromatic scale. In a 12-tone row, an atonal sound is created because no note is repeated in the entire row of 12 notes. This month, let’s explore a couple of exercises that use all 12 notes in a series of sweet-sounding, major-scale-based diatonic chords and passing chords. We’ll use the key of C major, and add passing chords between each diatonic chord generated from the C major scale.
Example 1 shows a common exercise using all of the triads from the C major scale: C, Dm, Em, F, G, Am, Bdim, C. Note that each triad arpeggio, or broken chord, is built from the ascending notes of the C major scale: C, D, E, F, G, A, B, C. If Ex. 1 seems unfamiliar to you, take time to practice the line slowly. To master this exercise, play the arpeggios in several positions on the neck. Once you have the written example under your fingers, create your own patterns using these chords and the exact notes of each arpeggio. Note that we’re only using triads (three-note chords), not 7th chords (four-note chords).
To review: Major scales use seven notes from our 12-note music system. Major scales adhere to a formula of whole-steps (W) and half-steps (H), which looks like this: W–W–H–W–W–W–H. Start on the note C, and count up a whole-step (up two half-steps, or up two frets) on your bass to arrive at the note D. Count up a whole-step (two frets) from D to the note E. Following the formula you see that the next note is a half-step up (one fret up, to the note F). Continue the formula until you’ve found all seven notes in the C major scale.
Now for the fun part. Let’s add a passing chord between some of the diatonic chords in the scale. Example 2 shows the ascending diatonic arpeggios of the C major scale, with passing chords between each of the diatonic chords that are a whole-step apart. Remember that there are seven notes in the major scale, leaving five notes where we could build passing chords:
The C#dim triad sits between the C and Dm chord in bars 1 and 2 (Ex. 2). This type of passing chord occurs in countless standards, often as a substitute for A7. Listen to songs like “I Got Rhythm,” “It Could Happen To You,” and “Easy Living” to hear this useful diminished passing chord in action.
The D#dim triad in bar 2 connects the chords Dm and Em. This passing chord is often used in “I Got Rhythm” and other standards. In bar 4, the pattern moves from Em to F, two diatonic chords from the C major scale. Since Em and F are a half-step apart, there can’t be a passing chord in between. The F#dim chord in bar 5 shows up in blues-based tunes as a passing chord between the IV (F) chord and the V chord (G7). In bar 6, the G#dim triad leads nicely from the sound of the C major scale into A minor, which is the relative minor of C major.
Bar 6 of Ex. 2 shows the only passing chord in the exercise that is not a diminished triad. The Bb major triad in bar 6 is a passing chord between two diatonic chords of the C major scale: Am and Bdim. The Bb leads smoothly into Bdim, which resolves perfectly into Cmaj.
Example 2 doesn’t outline a particular chord progression to a standard song, but it contains many typical passing chords and familiar sounds. You can build your harmonic prowess by getting this exercise in your ears and under your fingers.
Example 3 bops through the progression using only chord tones, a couple of inversions, and some rhythmic variation. Once you have this exercise down, write your own line over the progression. You can use just a few bars of the progression, or focus on two diatonic chords and one passing chord to compose your own line. Understanding passing chords will add color and harmonic swag to your goody bag of bass skills.
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