Using Slash Chords to Strengthen Your Bass Lines and Chord Progressions

Slash chords are an essential tool for adding variety to chord progressions and creating smoother movement from chord to chord. The slash refers literally to the chord symbol, as in G/B—usually spoken as “G slash B” or “G over B”—which simply means that you’re playing a note other than the root on the bottom of the chord. This small change to a chord voicing can have a big impact on the sound of a progression, as we’ll explore in this lesson.

We’ll build a library of slash chord shapes through a series of examples based on the chord progression to “A Whiter Shade of Pale,” Procul Harum’s iconic song from 1967, with its Bach-inspired organ accompaniment. The song uses slash chords throughout to create powerful descending chord movement and provides a useful platform for developing your slash chord vocabulary.

Weekly Workout is a series of monthly guitar exercises made up of interesting technical workouts that will get your fretting- and picking-hand fingers working in different ways, and offer musical studies that will help you visualize and explore the fingerboard.

Slash Chord Basics

The simplest type of slash chord is an inversion—that is, a rearrangement of the notes in the chord.

A C major triad, for instance, has the notes C (root), E (third), and G (fifth); when they are stacked in that order, with C on the bottom, that’s just called a C chord (or C major). Putting the fifth on the bottom, so the chord is spelled, say, G–C–E, creates the slash chord C/G. The fifth is a very common alternate bass note in any chord, so an inversion like this makes a subtle change in the harmony.

Another common slash chord voicing puts the third of the chord as the lowest note, as in C/E. Inversions with the third on the bottom sound less resolved than ones stacked on the fifth.

In addition to inversions, you’ll encounter slash chords that have a bass note that’s not in the basic triad, as in C/B or D/C. These sorts of slash chords are often transitional, creating bass movement leading to another chord; you might, for instance, play C to C/B to Am, with the bass descending in steps from C to B to A. You’ll see that kind of movement throughout the examples below.

As you play through these shapes, identify which note is on the bottom—a chord tone like the third or fifth, or another note—so you can learn to recognize the harmonic relationships.

Week One: ‘A Whiter Shade of Pale’

Now let’s jump in and try some slash chords in an example based on the intro/interlude progression in “A Whiter Shade of Pale.” The essence of the song is that chords change every two beats (or sometimes more often), and the bass line descends in steps almost nonstop; when the bass gets to the lower end of the register, it jumps up an octave and starts descending again. My fingerstyle guitar adaptation uses the same type of descending movement, and what makes that possible is—you guessed it—lots of slash chords.

First play the progression in C, the song’s original key. In Example 1, you’ll find a number of slash chord shapes with the fifth in the bass: Em/B, C/G, Am/E, F/C, and G7/D. The F/A and G7/B in measure 8 have the third in the bass. On the G/F in measure 5, the F—a note that’s not in a G triad—moves the bass line toward the Em that follows.

Start the example on a C and immediately descend in the bass: to Em/B, Am, C/G, F, and Am/E. At that point, you’ve hit your lowest bass note in standard tuning, so jump up to the fourth string for Dm, and descend again from there: the bass notes go to C, G, F, and E, before looping back up to D on the G7/D.

Note that the chord sequence in measures 1–6 accounts for the bulk of “A Whiter Shade of Pale.” In the verse (not shown), you play this six-bar sequence twice, and then once again to kick off the chorus.

For the main arpeggio pattern in these examples, pick the bass note with your thumb, followed by: index, middle/ring together, and index again.

Week Two: G and D

Once you’ve got this chord sequence under your fingers in the key of C, try it out in a few more keys. Through the following examples, the picking pattern is very similar to the one used in C, but these other keys employ some different slash chord shapes.

In Example 2, play the progression in the key of G, again using slash chords with the fifth in the bass (Bm/F#, Em/B, C/G, D7/A), with the third in the bass (C/E, D7/F#), and with a note outside the chord in the bass (D/C).

For the Bm/F# in measure 1, the shape could include a fifth-string B, but I’ve opted to leave it out so there’s more separation between the notes on the sixth and fourth strings. The same is true for the C/G in measure 4, with the fifth string muted. In some musical contexts, you may want to mute or skip strings like this in a slash chord to put more emphasis on your alternate bass note.

In other chord shapes in this lesson, too, I’ve left out strings that could be included. The D7/F# in measure 8, for instance, could have an additional F# note on the first string. I’m reducing this chord because I prefer its tighter sound—plus this fingering is a bit easier to play.

In measure 5, hold the D chord shape with an index finger barre and your ring finger so that you can easily add the middle finger on the fourth string for the D/C. In measure 8, slide the C shape up two frets for the Dadd4, and then play a C/E to D7/F# to G for a sweet, hymn-like closing cadence. The slash chord C/E, with the open sixth string, is surprisingly uncommon considering how easy it is to play, and it makes a nice transition to an F or, as in this example, a D/F#.

In Example 3, play in the key of D. Start with a closed-position D at the second fret and descend in the bass to the open fourth string, then continue down to the sixth string E. For the A in measure 5, use a first-finger barre to set yourself up for the following A/G.

Remember that shapes with no open strings are movable; that is, you can play them anywhere on the neck to sound different chords.

Week Three: A and E

This week, play the same progression in two other keys to work through additional slash chord shapes and moves.

Playing this progression in the key of A, in Example 4, offers some nice options for extending the chord voicings with open strings. Play the A in fifth position in measure 1 for a smooth shift to the C#m/G#, and continue the descent to the A/E. In measure 6, leave the top two strings open for a lush C#m7 and then an E7/B up at the sixth and seventh frets.

The key of E also presents opportunities to use more open strings. In Example 5, through the first four chords (E, G#m/D#, C#m7, E5/B), let the open second string ring while the other voices descend.

In measure 5, hold the fourth-fret barre with your ring finger through the B, B/A, and G#m7. The B7/F# that follows is a handy all-around slash chord shape that is a staple of swing rhythm—and it’s movable if you leave out the open second string.

With these chord shapes, only fret the strings you are using—you don’t have to hold down the full shape.

Week Four: Now Play it in F

For the last week of this workout, check out every guitarist’s favorite key, F, in Example 6. You may be surprised by how nicely this progression falls in F, with a lot of open-position slash chords (Am/E, Dm/A, C7/G, and more).

Start with an F shape on the top four strings and descend an octave through the first four measures, down to an F on the sixth string. In measure 4, keep your fourth finger planted on string 2, fret 3, while you change from Dm/A to Gm to Bb/F.

In measures 5 and 6, play the third string open through the C to C/Bb to Am7, creating a common tone as you move from chord to chord.

Now that you’ve worked with the progression from “A Whiter Shade of Pale” in six keys, you’ve covered quite a few shapes and combinations of slash chords. As you arrange other songs, try substituting slash chords in order to create a more connected sound in the progression, and to develop bass lines that move in smaller steps rather than jumping around. These subtleties in how you voice the chords will make your whole guitar part more mellifluous and satisfying.

Take it to the next level

Another good use of slash chords is to introduce additional movement into a progression. In this example, the basic harmony is D, Bm, G, A—one measure each, a classic I–vi–IV–V. I’ve split each measure in half to add a slash chord on beat 3 that moves the bass toward the next chord. The D/C# makes a nice transition to the Bm, for instance. Look for places like this where you can use slash chords to set up chord changes.