# Root, fifth and octave

*Module 9 · Lesson 2: Building bass lines · BazzLow*

> Use the root–5th–octave shape over major and minor chords.

Before this lesson: [9.1 Roots](https://bazzlow.com/en/building-bass-lines/playing-roots/) · [7.5 Triad shapes on the bass](https://bazzlow.com/en/triads-and-arpeggios/triad-shapes/)

One idea does most of the work for a bass player after the root: the 5th. It fits almost every chord.

## Why it works

The **perfect 5th** is the same in major and minor triads (lesson 7.2), so **root–5th–octave works over both**. It is the most common bass shape after the root alone. Over sus and power chords it is the safest choice (lesson 7.7).

From a root at fret *f* (lesson 4.3): the **5th above** is on the next string up, at fret *f*+2; the **5th below** is at the same fret on the next string down; the **octave** is two strings up, at fret *f*+2.

> **Diagram:** Root–5th–octave from C at fret 3 on the A string: the 5th above is G at fret 5 on the D string; the octave is C at fret 5 on the G string; the 5th below is G at fret 3 on the E string.

## Typical patterns in 4/4

- **1 – 5**, root on beat 1 and 5th on beat 3: the “two-beat” feel of country, folk and polka;
- **1 – 5 – 8 – 5**;
- **1 – 8**: octaves in eighths, the octave pattern of disco and dance.

> **Diagram:** The two-beat pattern 1–5 over C – Am – F – G, half notes.

> **Diagram:** The pattern 1–5–8–5 over the same chords, quarter notes.

> **Caution**: the plain 5th does not fit diminished (♭5) or augmented (♯5) chords. Use those chords’ own 5th.

## Try it

Play 1–5–8–5 in quarter notes over C – Am – F – G (one bar each). Then use the 5th below instead (5–1–5–8).

## New terms

- root–fifth
- two-beat feel
- octave pattern

Page: https://bazzlow.com/en/building-bass-lines/root-fifth-octave/