One of the most popular “Sesame Street” songs is “1,2,3,4,” a take-off on Feist’s 2007 indie hit. With a Muppet cast that includes Elmo, Rosita, some penguins and vacation-ready chickens, it’s the appearance that the Canadian singer-songwriter gets recognized for the most, she said. The “Sesame” version of the song, released in 2008, has over 240 million YouTube views; the original has about 13 million.

Whenever she’s traveling, a breathless parent will stop her for a photo. They say, “Do you mind, my 3-year-old has watched it 7,000 times,” Feist said. “And I say yes, but I always joke: You notice me because you’re a grown-up — the 3-year-olds are really only interested in the puppets. And without fail, the kids are just sort of looking at me like, who is this weird lady in the airport?”

In a phone interview, Feist described what it was like to perform on “Sesame Street.” “It kind of just felt like playing,” she said. “It really didn’t feel like, we’re filming something that will far outshine anything else that I will do in the rest of my life.” These are edited excerpts from the conversation.

Getting the call “It was a no-brainer. I handed myself over, knowing that they would rewrite the lyrics, and that the whole thing would be very much out of my control, because the caliber [of the show] has been so high my whole life.”