# Changing key

*Module 14 · Lesson 5: Beyond the key · BazzLow*

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

Before this lesson: [14.4 Borrowed chords](https://bazzlow.com/en/beyond-the-key/borrowed-chords/) · [5.6 The circle of fifths](https://bazzlow.com/en/major-scale-and-keys/circle-of-fifths/) · [5.7 Transposing](https://bazzlow.com/en/major-scale-and-keys/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.*

| Key | Neighbouring keys (V, IV) | Relative minors (home, V, IV) |
| --- | --- | --- |
| C | G, F | Am, Em, Dm |
| D♭ | A♭, G♭ | B♭m, Fm, E♭m |
| D | A, G | Bm, F♯m, Em |
| E♭ | B♭, A♭ | Cm, Gm, Fm |
| E | B, A | C♯m, G♯m, F♯m |
| F | C, B♭ | Dm, Am, Gm |
| F♯ | C♯, B | D♯m, A♯m, G♯m |
| G | D, C | Em, Bm, Am |
| A♭ | E♭, D♭ | Fm, Cm, B♭m |
| A | E, D | F♯m, C♯m, Bm |
| B♭ | F, E♭ | Gm, Dm, Cm |
| B | F♯, E | G♯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.

> **Diagram:** 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.

> **Diagram:** 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

- modulation
- closely related key
- pivot chord
- direct modulation
- step-up
- truck driver's change

Page: https://bazzlow.com/en/beyond-the-key/changing-key/