# Play along — chord changes (appendix)

Interactive version: [`songs.html`](songs.html). Part of [Theory and Practice](theory.md).

Songs are just a key's **diatonic chords** put in an order. Learn a handful of
**progressions** and you can play hundreds of songs — only the *key* changes.

> The magic fact: most pop songs reuse the **same few progressions** built from
> **I ii iii IV V vi vii°**. Master **I–V–vi–IV** and you already "know" *Let It Be*,
> *With or Without You*, and dozens more.

In the player, each chord shows as a block with its Roman numeral, name, the **note names** and
**scale degrees** (1 · 3 · 5) of that voicing, and a **→** line listing pitch-classes **shared with
the next chord** (when looping, the last chord compares to the first). A **mini keyboard** picture
shows the **exact voiced notes** (inversion from smooth voicing, root highlighted darker). All chips
share one keyboard window, so you can see the voicing shift by just a key or two from chord to chord.
Under the mini keyboard, suggested **L** and **R** fingerings (bottom → top) are shown for that
chord's inversion. The transport button is a single **▶ Play** / **■ Stop** toggle, and the current
chord's note names appear under the keyboard as it plays.

## How "chords come from the scale" becomes chord changes

1. Each key gives you 7 chords (see the [cheat-sheet](chord-cheatsheet.md)).
2. A **progression** is an order of those chords, written in **Roman numerals** so it works
   in any key: I–V–vi–IV means "1st, 5th, 6th, 4th chord of the key."
3. A **song** is one or more progressions looped. Change the key and it's the same song,
   just higher or lower — that's why numerals beat memorising letters.

## Famous songs by progression

Progressions are common, non-copyrightable patterns; only the chord order is listed (no
melodies or lyrics). Each song loads in its usual recorded **key and tempo** (tempos are
approximate) — hit **↺ Original key** in the player to snap back after transposing, or practice
in any key/speed.

### I – V – vi – IV — the "four-chord song"

| Song | Artist | Original key | ~BPM | In C |
|------|--------|--------------|------|------|
| Let It Be | The Beatles | C | 73 | C · G · Am · F |
| No Woman, No Cry | Bob Marley | C | 78 | C · G · Am · F |
| With or Without You | U2 | D | 110 | C · G · Am · F |
| Someone Like You | Adele | A | 68 | C · G · Am · F |
| Don't Stop Believin' | Journey | E | 119 | C · G · Am · F |
| Hey, Soul Sister | Train | E | 97 | C · G · Am · F |
| I'm Yours | Jason Mraz | B | 76 | C · G · Am · F |
| Take Me Home, Country Roads | John Denver | A | 82 | C · G · Am · F |
| Riptide | Vance Joy | A | 102 | C · G · Am · F |

### I – vi – IV – V — 50s doo-wop / ballads

| Song | Artist | Original key | ~BPM | In C |
|------|--------|--------------|------|------|
| Stand By Me | Ben E. King | A | 118 | C · Am · F · G |
| Every Breath You Take | The Police | A♭ | 117 | C · Am · F · G |
| Earth Angel | The Penguins | A♭ | 62 | C · Am · F · G |
| Heart and Soul | Hoagy Carmichael | C | 100 | C · Am · F · G |
| Blue Moon | Rodgers & Hart | C | 85 | C · Am · F · G |
| Perfect | Ed Sheeran | A♭ | 64 | C · Am · F · G |

### I – IV – V — the three-chord backbone

| Song | Artist | Original key | ~BPM | In C |
|------|--------|--------------|------|------|
| Twist and Shout | The Beatles | D | 126 | C · F · G |
| La Bamba | Ritchie Valens | C | 150 | C · F · G |
| Wild Thing | The Troggs | A | 100 | C · F · G |
| Blitzkrieg Bop | Ramones | A | 180 | C · F · G |
| Louie Louie | The Kingsmen | A | 122 | C · F · G · F |

### vi – IV – I – V — same chords, moodier start

| Song | Artist | Original key | ~BPM | In C |
|------|--------|--------------|------|------|
| Zombie | The Cranberries | E minor | 84 | Am · F · C · G |
| Numb | Linkin Park | F♯ minor | 110 | Am · F · C · G |
| Save Tonight | Eagle-Eye Cherry | A minor | 126 | Am · F · C · G |
| Otherside | Red Hot Chili Peppers | A minor | 122 | Am · F · C · G |

### V – IV – I — descending rock riff

| Song | Artist | Original key | ~BPM | In C |
|------|--------|--------------|------|------|
| Sweet Home Alabama | Lynyrd Skynyrd | D | 98 | G · F · C |

### ii – V – I — the jazz cadence

| Song | Artist | Original key | ~BPM | In C |
|------|--------|--------------|------|------|
| Autumn Leaves (turnaround) | jazz standard | G | 120 | Dm · G · C |

### The "Canon" — I–V–vi–iii–IV–I–IV–V

| Song | Artist | Original key | ~BPM | In C |
|------|--------|--------------|------|------|
| Canon in D | Pachelbel | D | 64 | C · G · Am · Em · F · C · F · G |
| Basket Case | Green Day | E♭ | 172 | C · G · Am · Em · F · C · F · G |

### 12-bar blues (I–IV–V)

| Song | Artist | Original key | ~BPM | Shape |
|------|--------|--------------|------|-------|
| Johnny B. Goode | Chuck Berry | B♭ | 168 | I·I·I·I · IV·IV·I·I · V·IV·I·V |
| Hound Dog | Elvis Presley | C | 175 | I·I·I·I · IV·IV·I·I · V·IV·I·V |
| Rock Around the Clock | Bill Haley | A | 180 | I·I·I·I · IV·IV·I·I · V·IV·I·V |
| Blue Suede Shoes | Carl Perkins | A | 165 | I·I·I·I · IV·IV·I·I · V·IV·I·V |

## How to practice

1. **Start in C or G** and slow the tempo — get the *changes* clean before speeding up.
2. **Right hand blocks first**, then try broken chords (one note at a time).
3. **Add the left hand** playing just the chord's *root* low down.
4. **Loop it** with the metronome on; change chords *in time* without stopping.
5. **Transpose** once it's easy — same progression, new key.

### Smooth voicing (voice leading)

The player has a **Smooth voicing** toggle (on by default). With it on, each chord is placed in the
**inversion** that moves the least from the chord before it: notes shared by two chords stay on the same
keys, and the rest step to the nearest chord tone — how a pianist actually plays. For *Let It Be*
(I–V–vi–IV in C) that turns the root-position leaps

- C: C–E–G · G: G–B–D · Am: A–C–E · F: F–A–C

into a barely-moving hand:

- C: **C4 E4 G4** · G: **B3 D4 G4** · Am: **C4 E4 A4** · F: **C4 F4 A4**

(about 9 semitones of total motion instead of 37). Turn the toggle **off** to hear every chord in plain
**root position**, matching the [cheat-sheet](chord-cheatsheet.md) shapes you're learning. A left-hand
root can always play the "true" bass underneath either way.

Chord shapes: [cheat-sheet](chord-cheatsheet.md). The theory: [Chords](theory.md).