See Outtakes From the Iconic Beach Boys Pet Sounds Photoshoot

The meaning of the title of the iconic Beach Boys album Pet Sounds has been up for debate ever since it was released 50 years ago, on May 16, 1966. Was it a reference to “pet,” meaning “favorite,” musical sounds? Was it a tribute to the PS in Phil Spector? Was it a dig at the idea that only a dog would hear the pitches the band played?

Regardless, the album’s famous cover art takes the title completely literally, bringing Beach Boys Carl Wilson, Brian Wilson, Dennis Wilson, Mike Love and Al Jardine to the petting pen at the San Diego Zoo on Feb. 15, 1966. (The spot has been pinpointed by Bob Egan, who maintains a blog tracking down the “exact locations of album cover photos.”) In honor of the album’s 50th anniversary and to promote a new collector’s edition, out June 10, Capitol Records has released these outtakes from the photoshoot.

Get your history fix in one place: sign up for the weekly TIME History newsletter

The day was covered in an April 1966 edition of KRLA Beat, a music-focused newspaper for teens, in a spread that featured photos of the five Beach Boys posing with giraffes, as well as the now-famous goats. The breathless story took the reporter (bylined only “Eden,” the pen name of Nikki Wine, who would go on to be a producer for Casey Kasem) to the San Diego Zoo with the band and photographer George Jerman.

“It took about half a million cabs to get us all to the zoo (would you believe about seven cabs??), where we discovered that nearly everyone there knew of our arrival, and had their pens and albums ready to be autographed by any of the five Beach Boys,” she wrote. “Once inside the zoo, we headed for the children’s zoo where we were led into a huge pen which contained various odd species of lambs, goats, llamas, and a few other animals which defied any sort of description!”

MORE: Read about Pet Sounds on TIME’s list of the 100 best albums since 1954

The day ended with a major storm, but not before the fateful shot had been taken.

“It had been a wild and wonderful day,” Eden concluded, “A day which found Dennis sharing a hot dog and fritos with a llama; a day which saw Brian in his first face-to-face encounter with a curious giraffe; a day which watched Mike eat every hot dog in the entire zoo; a day of Beach Boys, and a day which won’t soon be forgotten.”