Many of the Beatles’ most memorable ideas are variations on boilerplate riffs from rock, country, blues or R&B. The riff from “Day Tripper” derives from boogie-woogie. John Lennon cited Bobby Parker’s 1961 song “Watch Your Step” as the inspiration for both “Day Tripper” and “I Feel Fine.”
Boogie-woogie is based on dominant seventh chords. In “Day Tripper,” Lennon adds a twist by going one chord tone further, up to the ninth.
The diagrams below show the ninth chord built on E Mixolydian; on the left, shown on the chromatic circle, and on the right, shown on the circle of fifths.
To make a ninth chord in E Mixolydian, start on E. Skip F-sharp to land on G-sharp, the third. Skip A to land on B, the fifth. Skip C-sharp to land on D, the flat seventh. Finally, skip E to land on F-sharp, the ninth. The seventh chord sounds like rock, country, or blues. Putting the ninth on top gives a more sophisticated feeling, like jazz or funk.
Let’s take the riff in four pieces.
- First half of bar one: The riff starts on the root E. It then jumps up to the flat third, G. This note is not part of E Mixolydian at all; it’s not part of any E major scale. The flat third on top of a major-feeling tonality is characteristic of the blues.
- Second half of bar one: The bluesy flat third slides up to the “natural” third, G-sharp. The combination of G and G-sharp is characteristic of the major blues scale. Next, the riff outlines the rest of an E7 chord, out of order: the fifth B, the root E, and the flat seventh D.
- First half of bar two: The first beat is occupied entirely by the D hanging over from the previous bar. The second beat contains the big piece of harmonic excitement, the leap from B up to the ninth, F-sharp. The interval between B and F-sharp is the solid-sounding perfect fifth; it’s an unsurprising interval that lands you on a surprising pitch.
- Second half of bar two: the F-sharp hangs over a bit, and then the riff finishes by outlining the top half of the E7 chord: the fifth B, the flat seventh D, and the root E.
Boogie grooves usually chug along pretty steadily on the eighth notes, with a syncopation here and there to grab your attention. “Day Tripper” follows the formula closely. There are two rhythmic surprises. The last note of bar one, the D, is a long note that has a lot of emphasis. You’d naively expect it to fall on the downbeat of bar two, but instead it arrives half a beat early. The F-sharp in the second bar is also anticipated half a beat from the expected strong beat (beat three, the “invisible barline.”) The harmonic surprise complements the rhythmic surprise.
Another Beatles riff that puts a spin on a blues cliche: “Dear Prudence“