When writing and arranging songs, people often miss golden opportunities to create more interesting chord progressions because they always assume that the bass notes must be the roots of the chords. This month, we'll explore ways to expand your chord repertoire by changing the role that the bass plays in your chord changes.

We'll start by looking at simple progressions in which the chords move one to another in step-wise fashion, like so: CMaj, DMaj, Emin; or CMaj, Bmin, Amin. In these two progressions, we have a step-wise melodic bass line (C-D-E, or C-B-A), with the middle chord in each progression serving to connect the first and last chords. That is, in the second progression, the Bmin connects the CMaj to the Amin.

These step-wise progressions turn up all the time in songs; it's an effective way to move from one place to another, and they give us nice, melodic movement in the bass. However, these progressions do have one shortcoming: all the notes in the chords are moving parallel to one another, all in the same direction, all at the same time. While that"s not necessarily "wrong" or "bad," we can achieve the same step-wise motion in the bass while also using more interesting voice leading in the upper voices of the chords.

What if that middle "connecting" chord (e.g. Bmin in the second progression) were changed so that the bass note was no longer the root, but some other part of a different chord? For example, instead of a Bmin, we could have a GMaj with a B in the bass; B is the third of GMaj, so it will sound just fine in the bass. Now, we have a new progression: CMaj, GMaj with B in the bass, and Amin. Our melodic C-B-A bass movement is preserved, but now we have more subtle voice leading than we had before.

A shorthand way to say "GMaj with B in the bass" is "G over B." In chord charts, this would be written G/B. This is called a "slash chord" because it's written with a slash. When slash chords are written by hand, they're often written vertically, like a fraction: the G would be above the slash, and the B would be below.

Can you think of another chord we could put over B to connect Cmaj to Amin? How about E7? E7 is the "V" of Amin, so it will set up that chord nicely, and B is the fifth of E7, so it will sound good with the chord. Our new slash chord is written E7/B, and our new progression is: CMaj, E7/B, Amin. If you want a less dramatic transition, you could also try: CMaj, Emin/B, Amin.

Slash chords can be used for more than just step-wise bass lines. We can also use them to spice up musical sections where we're hanging out on one bass note for a while. Here's a good example: G, A/G, C/G, D/G, G. The G in the bass remains throughout, while different chords occur above it. (The G bass note in this example is called a "pedal tone," an old classical term that means a pitch that remains while other voices in the harmony move. In folk, jazz, and popular music, folks on the bandstand would just ask the bass player to "play a G pedal.")

Notice the second chord in the previous progression, A/G. This is a departure from the slash chords we saw earlier, because G isn't one of the notes in AMaj. (If it were an A7 chord, the G would be the seventh, but it's not a "7" chord, it's a major triad, one of a string of major triads being played over the G.) Nevertheless, AMaj sounds just fine when played over G in the bass, especially in this context.

A chord like A/G opens the door for us to try other interesting combinations. As a matter of fact, we can put any chord over any bass note we want, regardless of whether that bass note is actually in the chord, or even in the same key. Here are some fun ones: C/B; G/A; B/G; A-flat/G; E/G. Some of these chords are pretty dissonant, and require some finesse and harmonic sophistication to "handle" well. But they're cool, and worth playing around with.

As it turns out, we don't have to use slash chords only for step-wise bass lines and pedal tones — we can simply use slash chords as interesting chords unto themselves. They have a fascinating, unresolved quality that's useful when you want to build some tension. This is becoming increasingly common in contemporary songwriting. The late Jeff Buckley was a master of stringing together slash chords into beautiful progressions that bristle with restless energy, which he expertly managed by creating fluid voice leading, and touching down on rooted chords just often enough to give us a tonal center of gravity every now and then.

This principle isn't hard to put into practice. You can take the simplest progression and transform it completely by turning all the chords into slash chords. You can take a simple I, II, III progression (e.g. G, Amin, Bmin), and turn it into: G/A, Amin/D, Bmin/E; or into: G/B, Amin, Bmin/G. Even a I, IV, V can be rejuvenated by using non-roots in the bass: G/D, C/E, D/F-sharp.

One exercise you can try is playing an ascending major scale as a bass line, and over each bass note put a chord that doesn't have that bass note as its root. Here's an example: C/G, D/A, G/B, D/C, G/B, C/E, D/F-sharp, and Emin/G. In this example, the bass notes and chords are all in the same key, G Major.

However, I can use any chords I like, regardless of key. Here's just one example: E-flat/G, D/A, D-flat/B, E-flatMinor/C, B-flat/D, B/E, E/F-sharp, and back to E-flat/G.

Notice that, in all the examples so far, I've used triads in the upper part of the chords. But you can use fancier chords, too. A few examples: Gmin7/C; E-flatMaj7/G; Gmin7flat5/A.

Slash chords are simplest to play on a piano, with the right hand playing the chord and the left hand playing the bass. But slash chords can be and are played to great effect on the guitar as well.

In a band setting, you can let the bass player play the bass notes, while the chording instruments play the upper parts of the slash chords.

See what combinations you can come up with on your own. Enjoy!


Copyright 2003 by Richard Middleton.
All rights reserved.