Interval shapes on the bass
Play every interval as a fixed shape across strings, from any note.
On a bass, an interval is not a note name: it is a shape under your fingers. Learn the shape once and it works from every note.
One string
On one string, an interval of n semitones is n frets up. A major 3rd is 4 frets, a perfect 5th is 7 frets.
Across strings
Standard tuning in fourths makes every interval a fixed shape across strings. From a root at fret f:
| Interval | Same string | Next string up | Two strings up |
|---|---|---|---|
| m2 | f+1 | f−4 | — |
| M2 | f+2 | f−3 | — |
| m3 | f+3 | f−2 | — |
| M3 | f+4 | f−1 | — |
| P4 | f+5 | same fret | — |
| tritone | f+6 | f+1 | — |
| P5 | f+7 | f+2 | f−3 |
| m6 | f+8 | f+3 | f−2 |
| M6 | f+9 | f+4 | f−1 |
| m7 | f+10 | f+5 | same fret |
| M7 | f+11 | f+6 | f+1 |
| P8 | f+12 | f+7 | f+2 |
The shapes in bold are the ones used most. A dash means the shape exists but needs a large stretch or shift; the other columns are easier.
Going down
The same fret on the next lower string is a perfect 4th below. That note is also the 5th of the root, an octave lower: the classic “root–fifth below” bass move.
Why it works everywhere
Every pair of adjacent strings is a 4th apart (also B–E on a 5-string), so the shapes work on every string pair and in every key. The shapes do not tell you the note names, though. Know the name of the root and the interval, and the target note follows (lesson 4.1).
Start from A at fret 5 on the E string. Play each interval of the table with its “next string up” shape. Then move the root to C (fret 8 on the E string) and repeat, checking that the shapes have not changed.