Recorded in February 1964, the origins of "You Can't Do That" is from George Harrison’s love for American R&B. Lennon said: “That’s me doing Wilson Pickett.”
Lennon played the lead guitar on the song- while it was the first time George Harrison used his new 12 string, Rickenbacker- the second one ever built. Lennon commented: “I have a definite style of playing - I’ve always had. They call George the invisible singer. I’m the invisible guitarist.”
Instead of weeping as the narrator would have in previous songs, in this one, he tells his girl that if he catches her talking to another boy he’s going to leave her immediately. The song’s middle-eight demonstrates the speaker’s growing concerns that his beloved’s infidelities will expose him as a cuckold in front of his friends. Interestingly, his fear seems more rooted in the notion that he will be embarrassed before his peers- who admire him for landing such a delectable girlfriend- than in the reality that she has so easily betrayed him
Says Beatles scholar Ken Womack:
"The track captures the essence of the young John Lennon brilliantly—with its swaggering vocal, near-violent lyrics, fierce (and rare) Lennon guitar solo and mercurial structure. Harrison imbues the song with its insistent drive, while Lennon turns in a guitar solo with the appropriate rhythmic intensity to underscore the speakers’ anxiety over his beloved’s uncertain affections."
Adds musicologist Alan Pollack:
"The intimate direct-address of the lyrics is galvinizingly enhanced by the single-tracking of John's lead vocal, in which, if you listen for it specifically you'll note, he uses an astonishing number of varied shadings of tone. By the same token, the backing vocal part for Paul and George, with its subtext of "whatever John says goes double for us!", runs at cross-currents to the direct-address of the lead, even while it reflects and amplifies upon the choppy angularity of the melody and the rhythm track."
The track marked the beginning of the end of The Beatles’ miniature narrative about puppy love. It foreshadows a heavier, harder-rocking sound for the group that would infiltrate an increasingly large portion of their repertoire over the next few albums. It is an anti-love song which generates a kind of joy from the recognition of betrayal. An assertion of identity, the me against the rest. It embryonically anticipates the Beatles’ second period.
"You Can't Do That" has an off-beat attitude and a matching list of colloquial phrases rarely heard if ever, in a pop song of the time; e.g. "cause you pain", "leave you flat”, "it's a sin”. There's no talk admission here of his feeling hurt by the actual loss of the girl's love, no mention of any pre-existing feelings; for all we know, the other guy may truly be just a platonic friend and the whole thing just some over-reaction borne of terrific insecurity. As a singer Lennon leads by tugging, tossing, and teasing the beat, and he does the same thing with his guitar- setting up premises just to smash them.