Wheat's BassBook 5.2: A Comprehensive Method & Resource for the Electric Bass Guitar

Walking Bass

Walking is a style of bass playing most often associated with jazz. Books have been written on the subject, so I don't hope to cover all of the bases here, but I will attempt to give you what you need to know in order to start playing walking bass lines.

Rhythm: Four to the Bar
In 4/4 time, a typical walking bass line will play mostly quarter notes (i.e. four notes per bar, all on down beats). Advanced players add lots of rhythmic complexity, but for the sake of our examples, we'll be playing only quarter notes and only on the down beats. Each note will be different from the one before it (i.e. we will not repeat notes), which is what makes walking more difficulty than it sounds. This rhythmic simplicity adds driving force to walking bass lines.

Note Choice
Besides providing rhythmic drive, a major role of the bass in jazz is to outline the chord changes. So, as you might guess, most walking bass lines stick fairly close to the chord progression. In fact, the simplest way to walk is to play arpegios over each chord:

Scale Tones & Passing Tones
But playing arpegios alone (except maybe for certain ballads) doesn't add enough variety or produce the sound that most jazz listeners are familar with. To do that, you need to add other scale tones and passing tones. Scale tones are simply other notes from the scale that fits the chord. The A minor scale--the basis of our first chord--is A, B, C, D, E, F, G. So instead of just relying on the Am arpeggio, we can use any of the notes from that scale.

Passing tones are notes which are technically outside the scale which nevertheless help to make a smooth line. A common passing tone technique is to play a note on beat four of a measure which is one half step away from the next root. The note can be above or below the next root, and it can be either in or out of the scale on which the progression is based. The line below uses scale tones and passing tones:

The passing tones are what really make a jazz bass line swing. Jazz utilizes its own ideas of harmony, developed during its history, which varry somewhat from those used in "classical" music. Passing tones can be used anywhere in the bar, but they are very effective on the last note of any bar leading to a new root note. The passing note can be either a whole or a half step away from (above or below) the new root note, even if this means choosing a note outside of the scale. Notes outside of the scale, used in this way, add tension and color to the line. Passing notes point to the next chord, which helps the listeners (and the other players) anticipate it.

A Simple Formula
Taken together, these "rules" provide us with a simple formula for walking bass lines. Assuming that the progression you are encountering has only one chord per bar, you can use each of the four beats of that bar as follows:

If we apply this approach to our example, we can easily generate several workable walking bass lines. In fact, the example above follows the same logic.

Other situations
There are other situations which you will encounter when using walking bass lines. First, you'll often see bars which contain two (or sometimes more) changes. If there are two changes in a bar, the simplest way out is to play the root and then the fifth of each chord:

If you can think quickly enough, you can play play the root on the first beat of the chord and any other scale tone on the second beat. You might even want to try to play one of the notes which gives the chord its special sound. For instance, the flat third and flat seven are what give a minor seven chord it's sound.

In the first bar, I've chosen the root and third of Am7 followed by the root and seventh (though down an octave) of D7. In the third bar, I've chosen the root and seventh of Am7 followed by the root and third of D7. Bars two and four are the same as in the previous example.

Ballads
Slower songs often require that you play half notes (i.e. two beats per bar) instead of quarter notes. Since each note will be sustained longer, it's important to choose your notes carefully.

What to do when you loose your place
You can already tell that walking bass requires quite a bit of scale knowlege and anticipation. It's inevitable that you'll loose your place once in a while. The usual advice is to keep walking. A lot of bad notes will sound like daring passing notes as long as you eventually find your way back to the root. Keeping the forward rhythm going will not draw as much attention as stopping completely. If you find yourself hopelessly confused, you can either drop to a low E and pound on that until you hear the next change or you can stop entirely and jump back in.

What to play when you see chords you don't recognize
In the best of all possible worlds, you'd know every possible chord and a corresponding scale to play over it. But in the practical world, you'll ocassionaly get trown chords that, for all of your hours of preparation, you don't know how to handle. When you find yourself in such a situation, it helps to break the chord down to something simpler and remember some basics that you already know but might tend to forget in your pursuit of a perfectly sound bass line:

The root will always work
Skip the extensions, go for the basics: Is it major, minor, dominant, or diminished?
Except for diminished chords, the five will work.
Chromaticism is your friend.

To put our theory into practice, consider a real-world example: CMaj7#11. What would you play if you found a bar of this in a progression? The root (C) always works. In this case (since this is not a diminished chord) the five (G) works. That gives us two of the four notes we need. Simplifying the chord to CMaj7 (i.e. chopping off the extensions) should generate some chord tones (C, D, E, F, G, A, B). Now we only need one more note, and we can fill that with a passing tone.

A Real-World Example
All this theory becomes a lot more sensible when we tie it down to an actual tune. If you're already familar with playing blues lines, then it's not a big jump to tackle a tune like "Mr. P.C." from John Coltrane's Giant Steps (1960). The song has two sections, a "head" which includes a short melody which is repeated twice and a body where the instrumentalists trade solos. Then the head apears again at the end of the tune, to signify that it is coming to an end. Here's the chord progression for the head:

If we begin by playing noting but quarter notes (four to the bar), how shall we approach this progression? Well, for the Cm chords, we could play some combination of C Aeolian or C blues. That covers five of the twelve bars. But what do we do about those measures (3, 7, & 11) with two chords per par? C Aeolian and/or C blues will work for the first two beats, but what about beats three and four?

That Bb/C is what's known as a "slash chord." Composers use slash chords as an easy way to specify a certain chord inversion or voicing. In this case, the chord is Bb but the composer wants the lowest note in that chord to be C. As a bassist, you'll generally play the note to the right of the slash, though on this tune, the bassist tends to play Bb on beats three and four. Either approach would be correct.

Now we've addressed all but two bars: the Ab7 and the G7+9. Ab7 is easy enough. We generally use either a mixolydian or lydian mode for dominant chords. But to get the G7+9 you either need to know more about chord theory or you need to simplify. In this case, we'll take the easy way out and ignore the extension (i.e. the +9) and treat this chord as G7. So for G7, we'll play G Mixolydian.

Here's the progression again, this time with a workable walking line written out. This is a hypothetical line, not one taken from any recording.

An Analysis
Here's a measure-by measure analysis of the thinking behind this chorus. The chord or chords are listed first, then the scale approach(es).

Cm: Cm aeolian ascending line
Cm: Cm aeolian descending line
Cm Bb/C: root & third of the Cm arpegio over the Cm. Root & third of the Bb arpegio over the Bb.
Cm: C minor pentatonic with a chromatic approach note (F#) on the fourth beat
Fm: F minor pentatonic lick
Fm: F minor pentatonic lick continued
Cm Bb/C: same approach as for measure three
Cm: Cm Aeolian lick
Ab7: A lydian ascending line
G7+9: G mixolydian ascending line
Cm Bb/C: Root & fifth of the Cm arpegio over the Cm. Root & third of the Bb arpegio over Bb.
Cm: C minor pentatonic lick

Exercise
After you've tried the above examples and tried walking a bit over the same progression, try writing out some of your own lines. Sometimes taking the time to write out a line can show you ways of approaching it that you might not have noticed otherwise. If it helps you, write down a brief analysis of your line, as I have done above. This approach may seem overly academic, but it does work. Once you've written out a few, try walking your lines (and ones that you improvise) first at very slow tempos and then at increasingly faster tempos. Always work with a metronome. Choosing the notes is only half the battle. Your line has to give the tune its rhythmic pulse while enhancing the harmonic context.

Summary
At first, walking jazz lines can seem intimidating even to players with years of experience in other contexts (at least, that was my experience). But by understanding the basics of jazz bass lines and spending time working on your lines, you'll eventually be able to tackle the toughest songs at the most intimidating tempos.