Identifying I, IV and V chords

The I, IV and V chords are beginner-level music theory concepts. However, in my pop-oriented aural skills class, we are covering them in the context of the blues, where they are more complicated than they are in the standard tonal theory context. Let’s begin with a review of the basic I, IV and V from the major scale. Here they are in C.

Here’s how you build these chords.

• The I chord is built on the first degree of the scale, C. Move clockwise around the circle, adding every alternate scale degree: skip D and add E, then skip F and add G.
• The IV chord is built on the fourth degree of the scale, F. Move clockwise around the circle, adding every alternate scale degree: skip G and add A, then skip B and add C.
• The V chord is built on the fifth degree of the scale, G. Move clockwise around the circle, adding every alternate scale degree: skip A and add B, then skip C and add D.

Between them, these three chords use all seven notes in the major scale, establishing the key you are in unambiguously. If you have only I-IV or I-V, they could imply multiple different major scales:

• C and F could imply C major or F major.
• C and G could imply C major or G major.

In some musical styles, this ambiguity would be desirable, but Western Europeans  have historically preferred clear tonal centers.

There are uncountably many European folk songs and hymns that use I, IV and V, which have carried over into American tradition as well. It’s a cliche to say that pop music is all I, IV and V chords too. That may have been true at one time, but it has not been for many decades. Songs on the radio almost always include vi, or ii, or bVII, or sus4 chords, or sus2 chords, or V/V, or some other addition to or variant on the basic three. To find recent-ish songs that exclusively use I, IV and V, you have to go to artists who are deliberately folky, or to punk, or children’s songs.

Bob Dylan, who is highly deliberate in his folkiness, has written dozens of iconic I-IV-V songs. For example, “Visions of Johanna” is in A, and its only chords are A, D and E. (Sometimes the bassist puts a C-sharp under the A chord for variety, but it’s still A.)

This song is a good one for practicing your I, IV and V identification, because the pattern of the chords is long and unpredictable. Aural skills pedagogy materials suggest some methods for distinguishing these chords: for example, if the chord contains scale degree one (A in the key of A), then it can’t be the V chord, but if it contains scale degree seven (G-sharp in the key of A), then it must be the V chord. This test works well for classical music, but it is not reliable for pop, rock and folk, because the melodies in those styles do not necessarily “agree” with the chords. In a Bob Dylan song, singing A on top of an E chord often sounds perfectly fine. I suggest listening to the bassline instead, because in songs like this, it will be emphasizing chord roots most of the time.

“La Bamba” by Ritchie Valens is an iconic I-IV-V song in C, a repeated loop of C, F and G. Unfortunately, the tape got mastered a little fast, so it’s tuned really sharp and is hard to play along with.

Country music is a good place to find I-IV-V songs. “Coat of Many Colors” by Dolly Parton is in A, using A, D and E. Halfway through the song, she moves the key up a whole step to B, so it becomes B, E, and F#.

Reggae also features plenty of I-IV-V. “Red Red Wine” by UB40 is in D-flat, and it is a loop of Db, Gb and Ab. You could split hairs and say that the vocal melody often includes D-flat over the Ab chord, which implies Absus4, but let’s ignore that.

It’s common for the V chord in a I-IV-V tune to have a seventh on top of it. “Twist and Shout” by the Beatles is in D, and it has a similar structure to “La Bamba” and “Red Red Wine”: a loop of D, G and A for its main groove. Then the “ah ah ah” part is an arpeggiated A7 chord.

Okay, so that’s plain vanilla I-IV-V. How about the blues? People blithely describe it as being based on I, IV and V. This is sort of true, insofar as twelve-bar blues tunes do tend to use chords built on those three roots. There is an important difference, though: in the blues, all three chords are typically dominant seventh chords, and that produces a profoundly different sound from simple major triads.

My diagrams use a chord-scale explanation for the blues chords that is common in jazz pedagogy:

• C7 comes from C Mixolydian mode.
• F7 comes from F Mixolydian mode/C Dorian mode.
• G7 comes from G Mixolydian mode/C major.

I do not love this framing. It’s an after-the-fact explanation that jazz theorists came up with in the 1960s, and it’s a more accurate explanation of a tune like “All Blues” by Miles Davis than it is of folkloric blues. I prefer to think of the blues chords as belonging to blues tonality, where each chord is an equal-tempered approximation of a just intonation dominant seventh chord underlying melodies with flexible pitch zones. This theory argues that the “real” blues chords are I7 and IV7, and that V7 was grafted on later when blues merged with Western European musical traditions. Whether or not this is true, blues musicians do tend to favor IV7 over V7.

Let’s compare two recordings of “You Are My Sunshine.” The first recording of the tune is by the Pine Ridge Boys from 1939, and it’s in E, using the chords E, A and B.

Now here’s Ray Charles’ recording from 1962. He plays the tune in F. Rather than playing F, Bb and C, he uses F7, Bb7 and C7 (along with a few embellishments). But C7 only appears very briefly in the bridge; everywhere else in the tune, Ray plays Bb7 where you would expect C7.

Here’s a classic twelve-bar blues, “Standing Around Crying” by Muddy Waters. It’s in F, and it uses F7, Bb7 and C7.

“As Long As I’m Moving” by Ruth Brown is another (much faster) twelve-bar blues. It’s in D-flat, and it uses Db7, Gb7 and Ab7.

“Baby I Love You” by Aretha Franklin is a great example of a tune that uses I7, IV7 and V7 chords while not using the twelve-bar blues form. It’s in G, and the chords are G7, C7 and D7.

Identifying I, IV and V (or I7, IV7 and V7) is not difficult if you know that those are the only chords in a song. There are only the three possibilities, so you can simply listen to the bassline and use process of elimination. But how do you know if the song only uses those three chords and not others? That requires learning a lot of songs and internalizing how they sound, so you can recognize the same patterns when you hear them in unfamiliar places.