After 48 seasons, "Saturday Night Live" is a well-oiled machine … most of the time. Like any live show, there's bound to be mistakes. Whether it's the SNL cast breaking character during a particularly funny sketch, musical guests going off-book, or a curse word that slips past the censors, the long-running sketch show has seen its share of flubs and blunders.

Which means that longtime showrunner Lorne Michaels — who's been in charge at the show long enough to have almost slept through the meeting that launched SNL — has to run a tight ship in order to keep mistakes to a minimum. With only a week to plan and rehearse a full hour-long show, the writers and cast have to work diligently to get everything in order throughout the week, running through sketches multiple times before they're performed live and often scrapping skits that didn't work in dress rehearsal minutes before the actual show goes out.

Which means that although the cast almost always have at least some background in improv, they have to suppress that impulse as much as they can during filming. Or, at least Michaels would prefer it if they did.

'What We Do Here Is So Nailed Down'

The improv-troupe-to-SNL pipeline is well-known. Whether it's the Upright Citizens Brigade (UCB) theatres in Los Angeles and New York, LA's Groundlings theatre, or Chicago's Second City theater, Lorne Michaels and co. have sourced talent from the best improv groups in the US for decades, often putting potential SNL performers through brutal audition processes. But that doesn't necessarily mean they're looking for those improv skills to be put to use on the show itself.

Speaking to Vulture, the showrunner, who's overseen SNL since it debuted in 1975 (bar a brief hiatus in the '80s), explained how improv can actually make things difficult for a show that relies on everything being finely-tuned:

"There's a lot of training — UCB and all of that — and it's very good training. But what we do here is so nailed down that there's very little improvisation. Every line, every bit of dialogue, has a camera cut attached to it. If you're not where you're supposed to be, then they're going to miss the shot."

Plenty of cast members have run afoul of Michaels and his show's strict requirements. Interestingly enough, it was a performer known more for standup than his improv abilities that was infamously let go after deciding to put his own spontaneous spin on a live sketch. Damon Wayans joined the SNL cast in season 11 all the way back in 1985, but was fired the following year after he decided to play a police officer as a stereotypically flamboyant gay man at the last minute. Wayans, who had grown increasingly frustrated with his experience on the show and knew exactly what he was doing, said after the fact, via GQ, "I knew I was going to get fired for it. Lorne did the right thing."

Someone Has To Keep Things On Track

Wayans isn't the only person to go off-script and stoke Lorne Michaels' ire. In fact, it's not just cast members who can be swiftly removed from "Saturday Night Live," never to return. Back in 2003, Adrien Brody, fresh off his Oscar win for "The Pianist" hosted the show and decided it would be hilarious to introduce the musical guest, Sean Paul, as cringe-inducing parody of a Rastafarian, complete with fake dreads and over-the-top Jamaican accent. Oh, and he did so without telling anyone.

You can guess what happened next. Michaels reportedly banned the actor from ever returning to the show, though Brody claims he was never officially told to never come back. Still, he hasn't actually returned since that one and only time hosting. And considering how tightly-run SNL is and how painfully long Brody's Jamaican bit went on, that's not surprising.

I've had the chance to see SNL in-studio and witnessed first-hand how precisely planned the whole thing is behind the scenes. As soon as a commercial break hits, the stage is flooded by grips and gaffers moving scenery around with alarming speed and precision, rearranging the various areas of studio 8H to accommodate the next sketch. Even with all the dedication, things still go wrong. The night I was there, a sketch that relied on cutting between two sets within the studio was undermined when the camera cues were missed. Needless to say, any extra improv or extemporaneous additions would have made that scene even more chaotic. In other words, Michaels, who could well be leaving the show after the 50th season, may seem like he's being overly strict, especially for a comedy show — but when it comes to live TV, someone's gotta keep things on track.

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The post Why Lorne Michaels Doesn't Want Improv on Saturday Night Live appeared first on /Film.