You might have heard about four-chord songs. Numerous songs using one and the same chord progression, as Axis of Awesome ingeniously demonstrated. Or songs like Creep and Hit the Road Jack which use only four chords and still manage to be diverse enough to feel both compelling and complete.

But what if you tire of those same four chords? Can you change them into something new for your songs?

Let’s see if we can turn 1 progression into, say, 100, with a little help from music theory.

1. Scrambled eggs

Let’s take the doo-wop/ice-cream/Stand-by-me changes as a start.

1. C Am F G (I vi IV V)

This is a cyclical progression – the last chord leads back into the first. Once you get the ball rolling, the song moves forward by itself, so you can experiment starting the cycle from a different chord:

2. F G C Am
3. Am F G C

It’s a diatonic progression too – it uses chords in one key (C major). That means you can play the chords in any order you like, and they will still sound OK. For example:

4. G F Am C (backwards)
5. C F G Am (ascending bass)
6. Am G F C (descending bass)
7. C G Am F (Axis of Awesome example above), etc.

2. New Year’s substitutions

Once you exhaust the permutations of order, you may want to swap a chord here and there.

You can start by substituting a relative minor or major chord:

8. C Am Dm G (Dm for F)
9. Am C F Em (Em for G)
10. Am Am Dm Em (all minor)

You can also use the respective diatonic seventh chords:

11. Cmaj7 Am7 Fmaj7 G7

or the triads they contain if you omit the root note:

12. C Am Fmaj7 Bdim (Bdim for G)
13. Em Am7 F G7 (Em for C)

If you’re feeling bluesy, you can use only dominant seventh chords:

14. C7 A7 F7 G7

and, lo-and-behold, A minor has become A major (with a flat seventh).

Once we start using out-of-key chords, the real fun begins.

You can use a parallel minor or major chord (keep the root, change the quality of the chord):

15. C Am Fm G7 (Fm for F)
16. Cm Am F G7 (Cm for C)
17. Cm A7 Fm Gm (all changed)

The last example is dangerously close to a new key – the key of C minor. It’s possible to (roughly) maintain the function of the chords (tonic, dominant, subdominant) by modulating to a parallel key. In C minor, I vi IV V translates into:

18. Cm Ab Fm Gm (i bVI iv v) or
19. Cm Ab Fm G7 (i bVI iv V7)

if you prefer the brighter resolution of V to i.

Of course, nobody says you can’t move these chords around too (as in point 1. above) to get

20. Cm Fm Ab G7 (i iv bVI V7)

as in Amy Winehouse’s Back to Black (actually in the key of D minor).

In fact, rearranging the progressions in this point alone (multiplying scrambling by swapping, as it were) may actually be enough to get us to 100.

And we’re far from finished with substitutions!

You can also use suspended versions (sus2 and sus4) of the original chords which hide their major or minor colour and produce a much starker, raw sound:

21. C Asus2 Fsus4 G7/4
22. Csus4 Am Fsus2 Gsus4, etc.

Next, you can swap a chord with the secondary dominant of the following chord:

23. C C7 F G7 (C7 is the V7 of F)
24. C Am D7 G (D7 is the V7 of G)
25. E7 Am D7 G (E7 is the V7 of Am)
26. E7 A7 D7 G7 (classic evergreen bridge, circling in fifths)

Tritone substitution is also possible for the young at heart:

27. C F#7 F G7 (F#7 for C7)
28. C Am Ab7 G7 (Ab7 for D7)
29. C Am F C#7 (C#7 for G7)

And if you’re really keen, you can use altered dominant chords (throwing in augmented and/or diminished fifths and/or ninths):

30. C Am F G7/5+ (G7 with a sharp 5th)
31. C C7/5+ Fmaj7 G7/b5 (G7 with a flat 5th)
32. C C7/b9 Dm G7/5+ (C7 with a flat 9th)

3. Guided by voice leading

Once we get outside the safety of the key and start using altered or out-of-key chords, it’s always fun to look for opportunities for voice leading – movement by half steps (semitones) from notes in one chord to notes in the next (when the note does not remain unchanged).

So, if we only allow movement by semitones between certain chords, except in the bass, we get for example:

33. C Am6 F7 G (G from C goes to F# from Am6, E from Am6 goes to Eb in F7 goes to D in G)
34. C Adim F7 G (E from C goes to Eb in Adim, Eb from F7 goes to D in G)
35. C Adim Fdim7 G7
36. C A7 Fmaj7 G+

and if we take some of the substitutions above, we can have:

37. C C7/5+ F C#7 (C7/5+ and C#7 are substitutions and we have a line going from G to G# to A and back to G#)
38. C A7 D7 G7/5- (A7 and D7 are substitutions and we have a line going C-C#-D-Db and another one going G-G-F#-G)

The possibilities here are endless and the results – endlessly pleasing!

4. Pedals (on a wet, black bough)

If you’re in more of a modal mood, you can try playing the first chord (or some of its notes) over the roots of the original chords. That will give you:

39. C Am7 Fmaj7/9 G13

Alternatively, you can play the original chords over a bass pedal:

40. C Am/C F/C Cmaj7/9 (pedal C)
41. Am7 Am6 F/A G9/A (pedal A)
42. Csus4/F A+/F F G7/F (pedal F and an augmented substitute for Am)
43. C/G Am7/G F9/G G7 (pedal G)
44. C/E Am/E Fmaj7/E G6/E (pedal E!)
45. Cmaj7/B Asus2/B Fdim/B G7/B (pedal B!!!)

What do you think? Could it work over an even stranger pedal, say, F#? Try it!

5. Insertitudes

So far, we’ve stuck with the original number of chords – four.

But who’s to say we can’t have 2 chords per measure (or four) or 8 chords in the sequence (or 16)? We can string any number of the above changes together into longer chains. We only stayed with four to maintain a level of manageability.

But when the time comes to break out of the mold, we can start by inserting chords into the progression – one, two or as many as you like.

In point 2. above we saw the many chords you can substitute. Most of them, you can insert too.

You can insert a secondary dominant:

46. C E7 Am F G7
47. C Am C7 F G7
48. C Am F D7 G
49. C E7 Am C7 F D7 G G7

You can insert a diminished chord (basically a secondary dominant without its root):

50. C Am Edim F G
51. C Am F F#dim G7
52. C Abdim Am Edim F F#dim G Bdim

You can insert a parallel major or minor:

53. C Am F Fm G
54. C Cm Am A F G

You can add an altered chord:

55. C Am F G7 G7/5+
56. C C7/5+ Fmaj7 G7/b9

You can add sus2 and sus4 chords:

57. C Csus2 Am Asus2 F Fsus2 G
58. Csus4 C Asus4 Am Fsus4 F Gsus4 G

In the last example, Fsus4 uses a note (Bb) which is not in C major, so you can also use one of Rick Beato’s favourite triads – F lydian of Fsus#4 (F B C) – which has an augmented fourth (and a fascinating dissonance between B and C).

You can also insert tritone substitutes:

59. C Bb7 Am Ab7 G (Bb7 for E7, Ab7 for D7 replacing F)
60. C Am Gb7 F Fdim (Gb7 for C7, and Fdim replacing G (it’s actually part of the G7/b9 chord))

And so on.

When you try these, you’ll see how certain chords want to linger on, while others want to be gone fast (and others yet don’t want to be there at all).

You’ll find also that you’re instinctively trying to find a melody that goes with them – trying to fill in their backstory as it were – and it’s only natural that some progressions will work better than others.

In the end, you have to trust your ear. Let the irksome leave; let the sensible stay.

The purpose of this exercise is not to prove our knowledge of theory but to find as many ways as possible into the creative process.

It doesn’t matter if you stick with four chords or if the last one leads back to the first. Maybe it simply leads to the next part of the song.

What matters is this new matter you’ve made out of old matter.

6. Story lines and clichés

Speaking of melodies, stepwise melodies (line clichés) are a powerful glue for any chord sequence and they will often beg to emerge from it:

61. Am Am7 F Bdim (a B-A-G-F loop starting on the A)
62. C Cmaj7 C7 F Fm G7 (a C-B-Bb-A-Ab-G descending cliché)
63. C C7/5+ F F#dim G (a G-G#-A-Ab-G ascending and descending line)

Etcetera, etcetera.

We could keep going up to 100 by combining two, three or more of the above techniques, but I think you get idea. 100 is an artificial number anyway.

What’s real is the first step towards a new song you take each time you try something new, even if it’s just writing new lyrics for an old song or changing one chord in your favourite progression.

When you consider the fact that what we played with here is just one progression in just one key, you’ll see how much there is left to explore.

Studies like this one become demos and demos become finished songs. You just have to start somewhere.

So why not start here? Post a new progression or a demo using the above ideas in the comments below and I’ll be your hound dog… um, witness.