Ukulele Lesson: Understanding Chord Progressions


Chords tend to move in certain predictable patterns, and when you’re aware of these patterns you recognize them when you hear them in a song. This makes it easy to learn new tunes. I recently released a video called Understanding Chord Progressions for the Ukulele, in which I draw from a range of genres—pop, rock, country, jazz, and others—to teach how chord progressions work and, ultimately, how you can play a given song in any key.

In this lesson, I’ll focus on the I–vi–ii–V—a major-key chord progression so popular that over the years it has been given names like “ice-cream changes,” “dime-store progression,” and more. This progression is also at the heart of the A section to “I Got Rhythm,” the 1930 George and Ira Gershwin song whose harmonic structure has been used so often by jazz musicians and songwriters that it’s also been given a nickname, “rhythm changes.” But that’s for another lesson! Here’s everything you need to know about the classic I–vi–ii–V.

Playing With Numbers

Before you tackle the I–vi–ii–V, it’s important to know about the number system. Musicians often describe chord progressions by giving chords numbers instead of letter names. The numbers relate to the scale of a given key: In C major, C is the I, Dm the ii, Em the iii, F the IV, and so on, with uppercase Roman numerals representing major chords and lowercase denoting minor. You’re just going up the C major scale (C D E F G A B) and assigning numbers to the intervals. In the key of G major, take the G major scale (G A B C D E F#) and G is the I, Am the ii, Bm the iii, C the IV, etc.

The number system helps you see chord progressions in terms of interval jumps, like going from the I to the V, or between the I and the vi. Eventually you learn to hear these jumps: I–V has an unmistakable sound of its own, no matter what key you’re in. Once you start to understand chords in terms of numbers, you’re seeing the mechanics of songs—while grasping how music works!

Plug in the Chords

Using the number system, in the key of C, the I–vi–ii–V is spelled C–Am–Dm–G7, as shown in Example 1. (That last chord could also be played as G, but I prefer the sound of G7.) This chord progression has been the basis of loads of tunes over the decades—just to name a few, pop gems like “Blue Moon” and “Heart and Soul” in the 1930s, doo-wop ballads like “Donna” and “Earth Angel” in the ’50s,” hits like “Stand by Me” and “Please Mr. Postman” in the ’60s, and even “Hungry Heart” and “Every Breath You Take” in the ’80s.


understanding chord progressions example 1

Just to review: the numbers are I–vi–ii–V because:

  • C is I, if you’re in the key of C major
  • A is the sixth note of the C major scale, so Am is the vi chord
  • D is the second note in the scale, so Dm is the ii
  • G is the fifth note in the scale, so G or G7 is the V

As for how the I–vi–ii–V features into a longer context—namely, the eight-bar A section of rhythm changes—it’s often repeated three times, with a II–V–I (D7–G7–C in the key of C) closing out the section, as shown in Example 2.

Transpose It

Your next order of business is to strum the I–vi–ii–V from Ex. 1 in as many keys as you can, using the number system. To get you started, play it in F (Example 3a) and G (Example 3b).

As you strum through the chord changes, tell yourself, “Now I’m going to the vi chord, now I’m going to the ii, now I’m going to the V,” and you’re training your ear to hear those changes.

If you find yourself stumbling, here’s a more basic transposition exercise: Take a simple two-chord progression, such as the I–V—heard in tunes like “Jambalaya,” and play it in all 12 keys. To get you started, I’ve written it out for you in F (Example 4a) and in C (Example 4b).

By the way, some musicians don’t learn theory out of fear that it will get in the way of creativity. But the truth is that learning chord progressions doesn’t take any of the magic out of music. In fact, it just makes it more fun. If you can hear a tune and automatically play its chords, what’s not to like? I hope this lesson will help you hear the changes and gain a better understanding of music in general.

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