Back then, he recalled, the recording equipment "looked like an old roll-top desk with a couple of round knobs, a dozen vertical fitters and four equalizers." Today, he is comfortable at the helm of a million-dollar analog recording console with 192 motorized faders and adept in Pro Tools, the popular audio technology software used in music scoring and mixing.
"He knows the technology, but he also knows that it all starts with the music," says Armin Steiner, a Grammy-winning sound mixer whose film credits include "Revolutionary Road" and "Wall-E." "He has the greatest understanding of an orchestra and how it relates to a film than anybody."
Though laid-back by nature, Wallin is quick to bemoan the way the film business has changed over the years with its focus on blockbusters and sound effects. Although his film credits are dotted with lowbrow fare ("Date Movie," "Harold and Kumar Go to White Castle)," his favorite flicks remain firmly in the pre-1980s era: "The Wild Bunch," "Pat Garrett and Billy the Kid," "Magnum Force."
"It used to be the music was part of the story," he says. "The credits read dialogue, music and sound effects. Now they read dialogue, effects and music, and that's just so wrong. The emotion of the movie is the music when it's written correctly."
A few days after the Fox scoring session, Wallin is at Warner Bros., remixing the "Mission: Impossible" music that was recorded live the week before. The orchestra is gone, and only a handful of crew members are on hand.
Wallin adds more tambora drums and tones down the acoustic sitar on a complicated piece accompanying a scene in which stars Tom Cruise and Paula Patton attend a black-tie gala in a Mumbai mansion. "It's strong, but it could be stronger," he says.
On a break a few moments later, the octogenarian claims not to remember much about his long film career, but the stories tumble out with light prodding: the Cristal-fueled party after a long New Year's Eve scoring session for "King Kong"; the thrill of meeting Fred Astaire while working on Francis Ford Coppola's "Finian's Rainbow"; towing equipment up to the old Angeles Gun Club near Hansen Dam to record shotgun blasts for director Sam Peckinpah in "The Wild Bunch."
Peckinpah, Wallin says, was a "fiend" when it came to getting every sound right in his classic western. "If a girl came out with a little .22 or .35 automatic [in a scene], I had to have that exact caliber of gun," he said. "Each gun had its own sound, and the caliber for that gun was accurate because we recorded every one of 'em."
Wallin sticks to post-production music scoring these days, leaving the dialogue, gunshots and other sounds to editors, designers and re-recording mixers, who also make up the labor-intensive process of a film's sound. He speaks wistfully of his Warner Bros. days, when "you could bring your pants over to wardrobe and have them tailored [and] it was like a second home." Now a film's sound team, Wallin included, typically works freelance.
Yet except for the purchase of a programmable hearing aid a few years ago, the octogenarian shows no signs of slowing. He just wrapped "John Carter," with Giacchino as composer, and scoring sessions for TV's "Fringe" and "Alcatraz" are on the calendar for 2012.
His vague retirement plans include gutting and rewiring the 1950s beach house he just bought on Kauai and hanging out with his wife, Gay, four dogs and parrot at their hillside Malibu home.
But not just yet.
"I'm hoping it will be another two years," he says. "I'd like to go out as a big gun and not end with a whimper."