The Secret Power of I-IV-V

Lisa McCormick of recently wrote a great article on the power of the I-IV-V progression.  Understanding how you can use this progression in different keys will allow you to play virtually any song you want by ear.

Check it out-


Let’s face it, sometimes music theory just doesn’t seem very sexy.

But wait –

Have you ever lusted after figuring out how to play a song on the guitar, instantly, just by ear?

No sheet music, no tabs, no chord charts. Just you, the naked song, and the starry night. A match made in heaven.

Turns out, you may be a whole lot closer to that than you think.

In many cases, all you need is an understanding of the magic of “One, Four, Five”, in order to quickly figure out how to play thousands of songs, by ear.

What’s “One, Four, Five”?

“One, Four, Five” is common shorthand for Basic Chord Theory. And Basic Chord Theory is the hidden system behind what makes chords work together, within a key.

If you play a chord-based instrument (guitar, piano, organ, banjo, mandolin, uke, etc.), understanding Basic Chord Theory can be a real game changer for you and how you connect with your instrument.

What Does it Mean?

Let’s roll up our sleeves and dig in. Ready?

Every major key (like the key of C, for example), has a corresponding major scale (the C major scale).

Think: Do, Re, Me, Fa, Sol, La, Ti, Do.

(or: Sing the first line to the Christmas Carol ‘Joy to the World’, and you’ll have the major scale, backwards!)

Now, replace the Do, Re, Mi’s, etc. with numbers.

Do = 1. Re = 2. Mi = 3. Fa = 4. Sol = 5. La = 6. Ti = 7.

Sticking with the example of the key of C, and the C major scale, sing or play the scale starting on C.

Now, C = 1. D = 2. E = 3. F = 4. G = 5. A = 6. B = 7.

With me so far?

Now, single out number 1, number 4, and number 5.
(“One, Four, Five”, remember?)
And you get C, F, and G.

Finally, play those as major CHORDS (not just notes). You get a C major chord, an F major chord, and a G major chord.

Ready for the Sexy Part?

Now let’s use these three chords (the One, the Four, and the Five) to figure out how to play a song, by ear.

Let’s use the song ‘Happy Birthday’ as our guinea pig.

Play a C chord, and sing “Happy”, with your voice on the note G. Keep going into the song (…birthday to…), playing a C chord the whole time.

When you get to the word “You”, the C chord clashes with your voice! Ouch. Time to try a different option.

The rule of thumb here is to keep playing the same chord until you reach a point in the song where that chord does not work any more.

But rather than trying every other chord in the world to fix the problem, try using either the “Four” chord (F major), or, the “Five” chord (G major), to accompany the word “You” in the song.

Turns out the G chord sounds pretty good there (the “Five chord”).

Keep playing the G chord, and singing the song (…you…Happy birthday to…), and once again, when you get to the word “you”, it sounds like it’s time to change chords.

Again, don’t waste your time trying every chord in the world. Try your other two options, the C or the F. (the “One” or the “Four”)

Turns out the C chord sounds pretty good there (the “One” chord).

Stay with the C chord, and keep singing the song (…you…Happy birthday dear…), and now, when you get to the word “Lisa” (sorry, couldn’t resist!), it’s time to change chords again.

What are your options? F, or G. Let’s try the F, just for ha ha’s (the “Four” chord).

Sing my name (or, rather, the name of your true love) and play the F chord. Ah, sweet perfection.

Keep with the F chord, and keep singing the song. (…Lisa…Happy…).

When we get to “Birthday”, the F no loner sounds good, and the chord wants to change again. What’ll you go for? The C? The G?

(if you figured out that it is a C, you get an extra present on your next b-day).

Almost to the end of the song. Sing “To”, and play G. Sing “You” and play C.

Now congratulate yourself and make a wish!

This is the power of “One, Four, Five” in a nutshell, in the context of the key of C.

Five More Little Factoids You Need to Know:

1. This system works in every key, exactly the same way. Try working out the same song, in another key. How about the key of G?

2. This system will work for thousands of basic songs. Folk songs, pop songs, rock songs (remember “Three chords and an attitude”? THIS is what they were talking about!).

3. The more you practice working songs out by this system of trial and error, the better and faster you’ll get at it. Playing by ear will begin to come to naturally.

4. When “1”, “4” and “5” don’t cut it, try the The “2”, “3”, or the “6”. But here’s the rub: play these as MINOR chords.

5. Amongst musicians, chord-numbers are represented with Roman Numerals. Now that you understand the basics of the system, start using the nomenclature that the big kids use: 1 = I, 2 = II, 3 = III, 4 = IV, 5 = V, 6 = VI, 7 = VII.

6. What about the VII chord? It shows up far less frequently, for one thing. And when in does, it is played as a diminished chord. Let’s worry about that later.

Now, Go Forth and Play!

Now that you know the secret system behind “I, IV, V” (that’s “One, Four, FIve, silly), try it on some other common basic songs, just to get the hang of it. Yankee Doodle. Rockabye Baby. You Are My Sunshine. Amazing Grace. Joy to the World. Blue Suede Shoes.

Amaze yourself and impress your listener as song after song after song pours out of you and your instrument, seemingly like magic. Now, that’s sexy.

Lisa McCormick is a guitarist, recording artist, and guitar instructor for

Her tutorial, The Secret Power of I, IV, V, (and beyond!) can be found in the GuitarTricks Full-Access Section.

Click the image below to sign up for a FREE 14 day trial so you can check out Lisa’s The Secret Power of I, IV, V, (and beyond!) plus a ton of other great lessons, including one of the most comprehensive lists of song lessons