It’s the Beach Boys, not looking very beachy but sounding like they always do:
I will never understand the 50s and 60s fashion of band members all dressing alike. It just looks so weird now. Anyway, a group that did not look or sound like the Beach Boys but which had their own excellent song called “Don’t Worry Baby” was Los Lobos:
That was the first single from their first major labal album, Will The Wolf Survive?, and I’m so happy that it got regular airplay on then-San Antonio rock station KXZL, because I doubt I would have heard them otherwise. I’ve been a fan ever since.
I suspect the clothing was a holdover from the Big Band era. When you look at images of the Ellington, Basie, Goodman and Dorsey bands, they were all in light or dark suits.