But Spinney’s father disapproved, telling his son he was likely to “starve in a garret” if he pursued art. Students in his high school started a rumor that he was gay because he “played with dolls,” he recalls in the documentary. “I was so hurt, I was so angry, I looked out the window with tears burning in my eyes and said, “Someday, those bastards are gonna brag they knew me.’ ”

Spinney got his start in TV while he was stationed in Las Vegas with the Air Force in the mid-1950s, hosting “The Rascal Rabbit Show” on a local channel. The title character was a puppet built by his mother and inspired by the white rabbit in “Alice in Wonderland.” “It was on for only three months, and it paid $10 per week — $5 for each sponsor, Dairy Queen and GallenKamp Shoes,” he told me.

Following his military service, Spinney turned down a job as an animator at Disney; the wages were meager, and “I found out animation is incredibly boring,” he said. “You draw and draw and draw, and it’s only a few seconds done in a week.” He returned to Boston, where he played multiple roles on the show “Bozo’s Big Top” during the 1960s. It was around that time that he met Henson, who enlisted him to play two of the most central — and different — characters on “Sesame Street”: the pollyanna-ish Big Bird and bellyaching Oscar the Grouch, roles that Spinney has had for 46 years.

As Big Bird, Spinney performed seven times for several first ladies at the White House, had the opportunity to conduct symphonies in three countries and met countless celebrities. The role also led him to reconcile with his father. When his parents were in their 80s, they spent their weekly trips to the grocery store passing out “Sesame Street” postcards, proudly telling confused children, “We’re Big Bird’s mommy and daddy.”

As the audience departed the May 3 screening and Spinney’s “Sesame Street” colleagues in attendance gathered at a nearby steakhouse, Spinney and his wife, Debra, sat knee to knee in an all-white dressing room. He recalled an incident in the early 1970s when R.O.T.C. students at Georgia Tech dismembered part of his Big Bird ensemble while he took lunch. “Here was the bird down in the dirt, and his eye was kind of hanging off,” he recalled. “There was an area with probably as many as 100 feathers ripped off. And he looked totally dead. And I shrieked and cried. The colonel in charge of them said, ‘Don’t make a big deal about this.’ I said, ‘Right now there’s school buses are emptying, kids from all over the state are coming, 6,000 kids are going to be coming into this arena. And Big Bird is what they majorly want to see.’ ” The show had to go on. “We covered up the damage the best we could. My assistant glued on some replacement feathers which we always have. But one eye was broken so we had to sew that back on. It still didn’t work well, but we were able to perform.”