BazzLow
ENIT
Module 14 · Lesson 5

Changing key

Recognise how songs change key and how the bass leads into the new key.

Before this lesson: 14.4 Borrowed chords · 5.6 The circle of fifths · 5.7 Transposing

Songs do not always stay in one key. Recognising a key change in advance is one of the most useful things a bassist can do.

Modulation

A modulation is a change of key: the music settles on a new tonic, often shown by a new key signature or by many accidentals. Closely related keys are the neighbours on the circle of fifths and their relative minors. They differ from the home key by at most one accidental, so modulating to them sounds smooth.

The closely related keys of each major key: its two neighbours on the circle of fifths, and the relative minors of the home key and of both neighbours.
KeyNeighbouring keys (V, IV)Relative minors (home, V, IV)
CG, FAm, Em, Dm
D♭A♭, G♭B♭m, Fm, E♭m
DA, GBm, F♯m, Em
E♭B♭, A♭Cm, Gm, Fm
EB, AC♯m, G♯m, F♯m
FC, B♭Dm, Am, Gm
F♯C♯, BD♯m, A♯m, G♯m
GD, CEm, Bm, Am
A♭E♭, D♭Fm, Cm, B♭m
AE, DF♯m, C♯m, Bm
B♭F, E♭Gm, Dm, Cm
BF♯, EG♯m, D♯m, C♯m

Common techniques

  • Pivot chord: a chord that belongs to both keys is the hinge. C → G: Am is vi in C and ii in G, so the music can go C … Am → D7 → G.
  • Through the new key’s V7: play the dominant of the new key, then its tonic. From C to F: C7 → F. It is the same mechanism as a secondary dominant (lesson 14.3), but the music stays in the new key.
  • Direct modulation: simply start in the new key, often at a new section.
Bass clef staffThe roots of a pivot modulation C – Am – D7 – G: C fret 3 and A open on the A string; D fret 5 on the A string; G fret 3 on the E string.44CAmD7G
The roots of a pivot modulation C – Am – D7 – G: C fret 3 and A open on the A string; D fret 5 on the A string; G fret 3 on the E string.

The step-up

The step-up (the “truck driver’s change”, or “gear change”) moves the last chorus up a half or whole step. It is usually prepared by the new key’s V7 or simply played directly. It is common in pop ballads. A key change can be temporary, as in a bridge in another key, or permanent.

Bass clef staffA step-up from C to D♭: G7 (fret 3 on the E string) → A♭7 (fret 4) → D♭ (fret 4 on the A string).44♭♭G7A♭7D♭
A step-up from C to D♭: G7 (fret 3 on the E string) → A♭7 (fret 4) → D♭ (fret 4 on the A string).

For the bass

  • Know the new tonic before it arrives.
  • Lead into it with its V (or with an approach note).
  • Every shape moves: after a step-up, every note of the line moves up by the same interval (lesson 5.7).
Try it

Play roots of C – F – G – C, then C – Am – D7 – G – C – D – G. Notice where the music starts to feel at home on G. Then play I–IV–V–I in C followed by the same in D♭.

New terms