Sure, the film is a love letter to the American television institution, but Reitman also addresses the drugs, egos and premiere setbacks that nearly killed "Saturday Night Live."

Over the course of nearly 1,000 episodes, “Saturday Night Live” has given America some of its most successful comedians, iconic characters and quotable catchphrases. Now, just a year shy of the pop phenomenon’s 50th anniversary, director Jason Reitman returns the favor, turning an oral history of the show’s very first episode into a boisterous, delightfully profane backstage tribute. “Saturday Night” begins at 10 p.m. on Oct. 11, 1975, and ticks away in essentially real time to Chevy Chase’s delivery of the infamous opening line. Fine, but who’s playing Chevy Chase? Or Gilda Radner? Or John Belushi, for that matter?

The research is one thing, but Reitman — whose father, Ivan, directed his fair share of "SNL" legends and who always dreamed of writing for the show — sets himself the reckless challenge of finding enough funny people to play some of the most beloved cuties on TV. Miraculously, Reitman and casting director John Papsidera pull it off, with everyone reflecting the unique energy (if not always the exact look) of their characters. You might not cast them in an individual biopic, but as an ensemble, they're terrific. That's true whether you've never seen an episode or can remember organizing your Saturday nights around the show.

Ironically, the assignment required a different approach than that of “SNL” itself. The show’s original ensemble was drawn largely from Second City and National Lampoon, whose stars specialized in absurd personas and over-the-top impersonations. Reitman needed something more subtle here — actors who could channel their counterparts’ foibles and insecurities, taking icons and humanizing them.