Any history of TV’s landmark children’s series “Sesame Street” is going to have Muppets and songs, a lot of laughs and a few tears, and every letter of the alphabet — over and over again.

Marilyn Agrelo’s warm and sentimental appreciation of the venerable “educational” show,” “Street Gang: How We Got to Sesame Street,” takes us back to how it was created with an agenda, born of the better angels of ’60s activism.

We’re shown its world-changing premiere, led through gags and giggles, into controversy. And like the program itself, “Street Gang” touches on the “family” and deaths of cast members, reminding us how this very grown-up daily entertainment for children became an institution by never “talking down to kids.”

Using archival footage, vintage interviews and fresh chats with some of the minds behind it, we go way back to the origins of The Children’s Television Workshop and the foundation grant money that researched, focus-grouped and expert-consulted its way to a 1960s epiphany.

Let’s make a show about “what television would do if it loved people instead of trying to sell to people.”

Looking at research coming out at the time, a braintrust that included New York TV documentary producer Joan Cooney decided that one way to get kids, who loved TV then as much as they love it now, all on the same page when they started school was to “sell the alphabet to pre-school children.”

A show aimed particularly at inner-city kids would teach and tickle with animation, songs, sympathetic adult characters and most important of all — Muppets.

The film’s major revelations are not how hilarious, anarchic and charismatic the Muppets were and are. That’s been covered elsewhere. What’s fascinating here is remembering the lesser known figures who shaped the show that was to come.

Jaded New York director and producer Jon White, who was “over TV” when pitched the show, sees a catchy PSA for New York’s Urban Coalition and decides the show needs to be on an inner-city street scene set.

Hiring Black Philly talk-show host Matt Robinson as Gordon, the show’s major father figure upon inception, was more key than we realized at the time. He set the tone, gave the show “Street” cred with its main target audience — disadvantaged minority kids — and annoyed the hell out of Mississippi Public TV, which had to be bullied into carrying it, over racist objections, by commercial broadcasters in the state and noisy public demand.

The most adorable bit in this often adorable doc is watching Matt Robinson’s adult children, Holly Robinson Peete and Matt Robinson Jr., remember how cool it was to have a father on the most popular kids’ show on TV, and how troubling their questions about that were at that age.

“Who is this other little girl he’s holding hands with?” Holly frets, while Matt Jr. talks her down, just the way he did way back when.

The show was an instant success, with only tiny bits of pushback from this or that quarter. Orson Welles is seen telling Dick Cavett that “it’s the best thing that ever happened to television,” one of a flood of endorsements in a flurry of TV news pieces on the series as it debuted.

And a segregated America had to sit slack-jawed as a more idealized version of childhood and a vision of an integrated America played out, for 130 hours a year, right in front of their children.

Paul Simon sings an impromptu duet with a Black girl who doesn’t know who he is or “Me and Julio Down by the School Yard.” Jesse Jackson leads a call-and-response of kids from many races in “I AM somebody…We ARE beautiful. Beautiful children WILL grow up and make the whole world beautiful.” Loretta Lynn and Johnny Cash, Dizzy Gillespie and James Taylor and Stevie Wonder and Lena Horne lead the way to thousands of guest appearances on “Sesame Street.”

Cast member Sonia Manzano marvels at that very first episode, before she was ever hired — James Earl Jones sonorously reciting the alphabet, Grace Slick (of the Jefferson Airplane) singing ‘One two three four five six seven eight nine ten” and Bert & Ernie starting their quarrelsome bromance.

Did I mention what an unalloyed joy it is to see these people — outtakes from Muppeteers Jim Henson and Frank Oz, crusty Carroll Spinney joking around about Oscar the Grouch and Big Bird — and remember this show as those involved made it up as they went along? It is.

MPA Rating: PG (Language|Some Thematic Elements|Smoking)

Cast: Joan Cooney, Jon White, Holly Robinson Peete, Carroll Spinney, Sonia Manzano, Emilio Delgado, Frank Oz, Jim Henson, Lisa and Brian Henson

Credits: Directed by Marilyn Agrelo, based on the book by Michael Davis. A Screen Media/HBO Max release.

Running time: 1:47