The chord structure is the old classic rock standby, I-♭VII-IV-I. The progression comes from the Mixolydian mode, which is as defining for rock as diatonic major is for classical.
- F is the first note in F Mixolydian, so the chord built from it is called the I chord.
- E-flat is the seventh note in F Mixolydian, so the chord built on it is called the ♭VII (the flat is there to distinguish E-flat from the “natural” seventh you’d get in the major scale, which here would be E natural.)
- B-flat is the fourth note in F Mixolydian, so the chord built on it is called the IV chord. If you play I, ♭VII, and IV, you’re going to recognize many iconic rock and pop songs.
The left diagram below shows F Mixolydian on the chromatic circle. The right diagram shows it on the circle of fifths. The blue arrows show the roots of the I-♭VII-IV-I chord progression.
The “Hey Jude” loop is built from four phrases. Each one occupies more or less one bar, and each one comes with a chord: F7, E♭, B♭, and F7 again. To understand how you make the various chords from F Mixolydian, take a look at this diagram.
To make a chord, start on a note, then go around clockwise, skipping every other scale tone. The chord starting on F is F, A, C, E-flat. The chord starting on E-flat is E-flat, G, B-flat. The chord starting on B-flat is B-flat, D, F.
Here are the four phrases.
- First bar: a straightforward arpeggio starting on F, outlining a major triad.
- Second bar: Alternating G and F on top of the E-flat chord. The chord contains G as its third, so it’s a perfectly logical melody note. F is more surprising; it’s the second of the E-flat chord, not part of the basic triad. And yet, the F is is the note that gets held out for most of the bar. It turns the E-flat chord into E♭(add2), a richly jazzy sound.
- Third bar: Here’s where the real beauty part is. The melody in the third bar is exactly the same as the melody in the second bar, but the chord is different. G and F are the sixth and fifth of the B♭ chord, and the stable-sounding fifth is the one that gets held out.
- Fourth bar: The “He-ey Jude” phrase starts in on the tail end of the third bar, and the word “Jude” anticipates the downbeat of the fourth bar by a sixteenth note. It falls on the notes E-flat, D, and C, which are the fourth, third and second of the B♭ chord, and the flat seventh, sixth and fifth of the F7 chord. The rhythmic syncopation makes these multiple meanings possible.
This idea of the same note sequence having different meanings in different harmonic contexts is a powerful compositional strategy. It’s similar to the literary device of using the same words in different contexts with different meanings. The repeated melody in bars two and three works like the repeated last two lines of “Stopping by Woods on a Snowy Evening” by Robert Frost.
In classical music, and jazz too, the roots of chords tend to go counterclockwise around the circle of fifths. Each step represents a V-I cadence. Rock does that too, but it’s just as likely to move its roots clockwise on the circle. In this direction, each step represents a IV-I plagal cadence. The IV-I progression doesn’t have that sense of finality that V-I has; it’s more of a comma than a period. In loop-based music like rock, this is a good thing. You want an endless flow, rather than a narrative with a beginning and end.
Some classical theorists see the “Hey Jude” progression and say, well, you’ve got an F7 and a B-flat, so clearly we’re in the key of B-flat, and the F7 is the V7 chord. In common-practice-era classical music, and jazz too, the clearest way to determine what key you’re in is to look for V-I cadences. Also, in classical, you can’t use a dominant seventh chord as a tonic because it feels unstable. In rock, though, the rules are different. Due to the influence of the blues, dominant seventh chords feel perfectly stable. F7 is very obviously the I chord in “Hey Jude,” because it sits in the metrically strongest position in the phrase, and it ends the phrase too. The I-♭VII-IV progression keeps you floating around within the Mixolydian mode, rather than landing you squarely on a major scale.
More iconic Mixolydian I-♭VII-IV simples:
- “Satisfaction” by the Rolling Stones
- “Sweet Home Alabama” by Lynyrd Skynrd
- “Sweet Child O’ Mine” by Guns N Roses
Try singing the “na na na” riff over any of these tunes, it’ll fit perfectly.
By the way, singing “na na na” is a bit of a trope in pop and rock.
