Bass Arpeggios: Triad and Seventh Chord Shapes

An arpeggio is a chord played one note at a time. Guitarists and pianists play chords as stacks of notes, but a bassist plays mostly single notes, so arpeggios are how a bass player "plays the chord". Almost every strong bass line is built from chord tones on the important beats, and arpeggio shapes are the fastest way to find those chord tones anywhere on the neck.

Because the bass is tuned in fourths (E1 A1 D2 G2), every shape in this lesson is movable: learn it once with one root, slide it to another fret and you have the same chord quality with a new root.

Triad shapes

A triad has three notes: root, third and fifth. The quality of the third and fifth decides the chord type.

Here are the four triads with the root on the E string at fret 3 (G1), each finished with the octave on the D string:

Learn these as distances from the root:

• Major third: one string higher, one fret lower (G to B: E string fret 3, A string fret 2).
• Minor third: same string, three frets higher (G to Bb: E string fret 3 to fret 6).
• Perfect fifth: one string higher, two frets higher.
• Diminished fifth: one string higher, one fret higher.
• Augmented fifth: one string higher, three frets higher.
• Octave: two strings higher, two frets higher.

The fretboard below shows every G, B and D on the neck. Find the shape from the tab, then look for the same three notes in other positions: the triad repeats all over the neck.

Seventh chord arpeggios

A seventh chord adds a fourth note, the seventh, on top of the triad. These five types cover almost all of jazz, soul, funk and pop harmony.

All five with the root at E string fret 8 (C2), each ending on the octave at D string fret 10:

Notice how little changes from one chord to the next. Cmaj7 to C7 moves only the seventh down one fret. C7 to Cm7 moves only the third. Cm7 to Cm7b5 moves only the fifth. Cm7b5 to Cdim7 moves only the seventh. Practising them in this order trains your fingers and your ears at the same time.

Bass music is written one octave higher than it sounds, so the Cmaj7 arpeggio above, which starts on the sounding note C2, looks like this on a bass part:

One-octave and two-octave fingerings

One octave in one position

Use one finger per fret: in the C shapes above your index finger covers fret 7 (or 6), and the other fingers fall on the next frets. For the major triad with the root on the A string, a compact shape is root with finger 2, third with finger 1 on the next string, fifth and octave with finger 4:

Keep the fingers close to the frets and let the thumb rest behind the neck around the middle finger. Do not squeeze: the string only needs to touch the fret.

Two octaves with a shift

A two-octave arpeggio needs a position shift. Shift on a note you can reach comfortably and keep the rhythm even through the shift.

Play A1 with finger 1, C2 with finger 4 and E2 with finger 3. Shift on A2: play it with finger 1 at D string fret 7, which puts your hand in 7th position. C3 (finger 4) and E3 (finger 3) are now under your fingers, and the last A3 at G string fret 14 is a slide with finger 3 or a small shift. Practise the descending version too: coming down is where most shifts get sloppy.

Inversions on bass

An inversion means a chord tone other than the root is in the bass. For a bassist that is a real choice: when you play E under a C chord, the whole band sounds C/E (C in first inversion), even if the guitarist plays a normal C shape.

First inversions sound lighter and are great for smooth stepwise bass lines. Second inversions sound less settled and usually appear just before a resolution. See the chord inversions lesson for the full theory.

Using arpeggios in bass lines

Running full arpeggios up and down every bar sounds like an exercise, not a bass line. Use them as raw material:

• Chord tones on strong beats. Put the root on beat 1 and another chord tone (third or fifth) on beat 3.
• Choose a direction. Go up through one chord and down through the next, so the line stays in one area of the neck.
• Leave notes out. Root-fifth-octave without the third works for any major or minor chord.
• Use the seventh as a pointer. In jazz and soul, the seventh on beat 4 leads naturally to the next chord.

Here is a quarter-note arpeggio line over C, Am, F and G in the low position, one bar per chord:

And a ii-V-I in C using seventh-chord arpeggios. Each bar starts on the root, and the whole line stays between frets 2 and 7:

Now hear the same progression as a generated walking line, and compare which notes come from the arpeggios:

Practice

1. Triad cycle: play major, minor, diminished and augmented triads from every fret of the E string from 1 to 8, with a metronome at 70 BPM.
2. Seventh ladder: play maj7, 7, m7, m7b5 and dim7 from one root, then move the root up one fret and repeat.
3. Two octaves: play the two-octave minor arpeggio in A, then in Bb and B, with the shift on the same beat each time.
4. Inversion line: play C, C/E, F, G and back to C, choosing the bass note from the inversion tab.
5. Write a line: use only chord tones over a four-chord progression from the progression player.

Related lessons: Triads, Seventh chords, Chord inversions, Bass basics, Bass scales and modes, Bass lines over progressions, Walking bass.

Tools: Scale explorer (arpeggios on the bass neck), Chord builder, Metronome, Fretboard trainer.

Exercises: Bass arpeggios, Seventh chord arpeggios, Root and fifth, Octaves, Spell triads, Spell seventh chords.

Follow the 8-week intermediate bass path to put arpeggios into a weekly routine.