If there’s a word that best describes Questlove‘s herculean effort to encapsulate the entirety of five decades of Saturday Night Live‘s musical legacy in one three-hour-long documentary, it’s diligence.

That’s on full display just in the first six minutes of the film, which debuts with an extensive cold open mashing up decades of performances by everyone from Billy Preston to Sabrina Carpenter, Gwen Stefani to Run-DMC and Dave Matthews Band to Queen, the whole number cohesively mixed to work with one another.

“It’s literally taking note of every musical moment, every note,” Questlove (real name, Ahmir Thompson) tells THR as he hands over his phone to reveal a seemingly endless scroll of memos detailing genre, keys and tempo. The cold open took about 11 months to make. The notes we see, he says, are likely just from 1975 to 1985. “It’s every song ever played and then figuring out a 10,000-piece puzzle.”

Ladies and Gentlemen … 50 Years of SNL Music was supposed to be a bit of a layup for the musician-director compared to, say, the exploration of the self-sabotage of Sly Stone in Sly Lives! (aka the Burden of Black Genius), with this project originally intended as a more modest collection highlighting 50 of the most iconic performances in the show’s history. As that cold open alone reflects, that didn’t happen. In Questlove’s own perfectionism and, as he says, “self-sabotage,” it had become a deep dive into the show’s consistent window into pop culture as well as the weekly struggles and triumphs the show has created for those who’ve taken part.

“I felt like, ‘We’ll just make a really sophisticated clip show,’ and mid-recording, we started to notice an arc that keeps happening with every single story we get,” Questlove says. “It’s a story of someone being presented with a daunting challenge, and it’s met with hesitancy, and it’s met with fear and trepidation. Is Jimmy Fallon going to knock on Mick Jagger’s door and change his life? Will Eddie Murphy don a James Brown wig and sing about bubbling hot water for 30 seconds and change his life? What the hell’s Kanye going to do when he wears that hat on national television? Elvis Costello changing up the song in 1977 — every story we go over, there’s a risk factor.”

Once we decided to get rid of the 50 best performances, I was like, “I’m gonna watch three to seven episodes every day.” That’s when I realized, by 1984, especially when Eddie Murphy came aboard, there are way more iconic musical comedy sketches than there are musical performances. Once I started making a list of every performance moment, the comedy stuff was way in the lead. It became clear that we had to focus on both.

I’ve been at 30 Rock — 30 Rock University — for going on 17 years now. A lion’s share of my time off is making excuses to be [back] on the eighth or ninth floors. … But the best way to experience SNL is absolutely [watching it] on television because it’s just two different experiences. The jokes land better on television because it’s one of the best-mixed shows on TV. It’s silent in the studio, you have to be more quiet and not laugh as hard or you won’t hear the next joke. But when the commercial comes on, that’s when I come alive. It’s like watching a demolition derby of five different ecosystems, and one false move and boom. (Hits his hand on the table.) Will a teamster crash into a prop guy? Will the wardrobe lady safely get our host over the musicians and back to the quick change booth? Watching the ecosystem and watching how it works, that’s the thing that excites me.

You also highlight in the documentary how much more chaotic it gets when the musical guest is hosting.

The Lady Gaga show [in March] was probably the one thing that I don’t think historian nerds are taking note of. She did a rarity: She’s in every single sketch when she hosted, and the musical presentations were elaborate. She has mere seconds to think. People ask what I would add now that the doc is shut; that would be it. When we shut the show down, Charli XCX [who hosted and was musical guest in December] was recording, and I begged production to let me go in post and just add one frame of Charli in there — it was such a great episode. This was literally four or five days before airing, I was like, “Look, I know we locked film already, but dog, let me fix this one frame,” and I got my wish.

You’ve probably watched more Saturday Night Live music moments than anyone else on the planet except maybe Lorne Michaels. Is there a performance you think is most emblematic of the show?

The performance that really just blew me away I actually decided not to put in the doc because if I couldn’t put the whole five-minute performance in, you wouldn’t have felt the energy of it. I didn’t think I was going to learn anything from Neil Young’s “Rockin’ in the Free World” in 1990, but it’s just looking at five guys, just the equivalent of musical anvils dropping on your head. It’s one of the loudest, most energetic performances I have ever seen.

This story first appeared in a May stand-alone issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.