Proof that in 1977, Brian's voice hadn't yet been damaged (since he sure as heck sounds like 1964 Brian) and he could still use his falsetto, he just chose not to.
Brian Wilson: "Pick him up, please." *THUD* *Laughter* Brian Wilson: “Hey Chuck, is it possible we can bring a horse in here without… if we don’t screw everything up?” Chuck Britz: “I beg your pardon?” Oh my God, Brian...