When The Beatles quit touring and began focusing more on creating music in the studio, track by track, their musical roles became less clearly defined. Sometimes Paul McCartney played drums ("Back in the U.S.S.R."). Sometimes Ringo Starr played the comb and paper ("Lovely Rita"). Sometimes John Lennon played Yoko ("Revolution 9").
One role that remained fairly well established, however, was Paul as the bass player. He had arguably the greatest command of the instrument, and knew exactly how to weave bass lines into songs in such a way as to make the bass part memorable (see, for example, "Nowhere Man," "Michelle," or "Paperback Writer").
Here are five Beatles songs where you'd swear Paul was playing the bass, but he's actually not. (Thanks to our friends at The Beatles Bible for supplying the well-researched data on these songs!)
Carry that Weight
A memorable part of the so-called "Abbey Road Medley," it's hard to imagine "Carry that Weight" without that driving, arpeggiated bass line thumping away. It sounds a lot like Paul's style, but in fact, he was busy pounding away at the piano and supplying rhythm guitar for the track. The bass part is actually played by George.
Two of Us
This sweet acoustic duet between John and Paul does feature a lower guitar part (heard especially in the outro of the song) that sounds like a bass guitar being played in its higher register, but what we have here is the perfect setup for a Beatles trivia question. There actually isn't a bass guitar on this track, but George did supply some low-note riffs throughout the song on his electric guitar, so technically, George played "bass" on this song.
She Said She Said
The bass part in this song is so McCartney-eqsue that it's practically impossible to believe it isn't Paul playing the part. The continual movement of the bass line, the classic "passing notes," and the overall prominence of the part all suggest a McCartney performance, but as Paul himself recounted to Barry Miles in Many Years from Now:
"I'm not sure but I think it was one of the only Beatle records I never played on. I think we'd had a barney or something and I said, 'Oh, [bleep] you!' and they said, 'Well, we'll do it.' I think George played bass."
It was indeed George playing the bass on this song.
Old Brown Shoe
The bridge of this song showcases a rollicking bass line that practically begs the listener to envision Paul playing the part, but in reality, he supplied the more prominent piano part on this song, as well as some lead guitar parts that double the bass line in the bridge. But the bass is being played by George, not Paul.
This may be something of a technicality, much like "Two of Us," in that there is no actual bass part being played on this track. But you can hear the bass throughout the song, right? Especially in the transition to the bridge, there is a very obvious set of low notes dancing around and moving up the melodic line, but the only stringed instrument being played in this song is an acoustic guitar, supplemented by some percussion supplied by John and Ringo. Those low notes? That's Paul, using his voice on syllables like "dum" and "doo" to provide a "scat" bass line.