While many rank “Yesterday” among the greatest songs ever written, Paul McCartney didn’t want to release it as a Beatles single in 1965. Paul pointed to the arrangement, which featured a string quartet and no one from The Beatles other than him.
“We were a little embarrassed about it,” Paul later said in an interview from Beatles Anthology. “We were a rock ‘n’ roll band.” While The Who’s Pete Townshend might disagree with that take, Paul got his wish about “Yesterday” remaining a non-single (at least on the U.K. market).
The following year, Paul wrote another outstanding composition that ended up with a string accompaniment: “Eleanor Rigby.” But this time around producer George Martin suggested taking all the guitars out completely.
Source: cheatsheet.com