This was underrated at the time, being released in 1964 as the B-side of the Beach Boys’ first US chart topper I Get Around, reaching No 24 in its own right. It was written by Brian Wilson and his frequent collaborator Roger Christian and produced by Wilson, who was also the falsetto lead vocalist.
Beach Boys: Don’t Worry Baby
Square
I believe Brian wrote this with the Ronettes in mind, but they never recorded it.
Ronnie Spector recorded it many years later and there is a famous clip of Brian hearing it for the first time and being stopped in his tracks:
https://www.youtube.com/watch?v=9JMdw__a77A
Ronnie’s version is great by the way, especially the live version she did a few years ago on “Later with Jools Holland”.