Aarcflick

 To celebrate the 50th season of “Saturday Night Live,” it’s not enough to cram 90 minutes of live television into six days (an already Herculean feat). Plus, the venerable variety show is flooding the zone with spectacles of its pop-cultural power. Following Jason Reitman’s hagiographic film “Saturday Night” and preceding next month’s three-hour broadcast from Studio 8H comes the four-part docuseries “SNL50: Beyond Saturday Night.”  Executive produced by Oscar winner Morgan Neville (“20 Feet from Stardom,” “Roadrunner”), the show is the latest step in NBC’s marketing campaign to celebrate the anarchic experiment turned established institution. But 50 years later, the legend of Lorne Michaels’ merry circus has already been celebrated — many times over. (The 40th season also had a star-studded anniversary party, giving this round of toasts a distinct sense of déjà vu.) “SNL50” adds little to this half-century of anecdotes, oral histories and archival material. Instead, it embel...