'Saturday Night Live' cruises into middle age

 It's called "Saturday Night Live" and it's made in New York, but as the storied US comedy sketch show cruises into middle age, it's more like Saturday Night all the time -- and everywhere.
The program's 40th season kicks off this weekend with "Guardians of the Galaxy" star Chris Pratt as host, pop princess Ariana Grande as musical guest and its influence as strong as ever, thanks to the digital era.
Skits performed by the cast of the NBC show and the revolving group of A-list hosts -- from Justin Timberlake to Tom Hanks -- regularly go viral on Twitter and Facebook.
The list of past regular cast members reads like a who's who of Hollywood comedy: Bill Murray, Chevy Chase, Eddie Murphy, Chris Rock, Tina Fey, Kristen Wiig and Will Ferrell, to name a few.
The guiding force over the decades has been the show's Canadian-born creator, Lorne Michaels, a hands-on producer who, at 69, has guided his pride and joy to the pinnacle of American entertainment.
"Lorne and the show know what they want to be," said James Andrew Miller, co-author of "Live from New York," a history of "SNL" as told by its stars, guests and Michaels himself.
"The show has kind of a palette that it operates from, and it's served them well," he told AFP.
"The big variable in all of it is just how funny it is. Some weeks it's hysterical, and some weeks it's not. But I think people understand the format and find comfort in it."
On average, 7.1 million Americans tune in to "SNL" every week, according to Nielsen ratings cited by NBC -- not including viewers in 200 foreign markets or those who catch up online.
It has also inspired offshore spinoffs in such unexpected sketch comedy outposts as Brazil, Italy and Japan.
And as an incubator for new comic talent, "SNL" -- with more Emmy award nominations than any other program in TV history -- has few rivals.
- Branching out to sitcoms -
The show's stars have made the jump to successful sitcoms and big-screen hits.
On the small screen, there's "SNL" alums Andy Samberg on "Brooklyn Nine-Nine" and Amy Poehler on "Parks and Recreation".
Fey's "30 Rock" -- co-starring Alec Baldwin, a frequent "SNL" guest host, playing a character inspired by Michaels -- wrapped up a seven-season run last year.
A generational changing of the guard on weekday late-night television has six-season "SNL" veteran Jimmy Fallon hosting NBC's "The Tonight Show" and former "SNL" cast member and head writer Seth Meyers on "The Late Show."
Nearly a dozen movies grew out of "SNL" sketches, including "The Blues Brothers" starring Dan Aykroyd and the late John Belushi, and "Wayne's World" with Mike Myers and Dana Carvey.
"It's almost like if you want to be a major motion picture comedy star, you've got to go through 'SNL'," said Doug Spero, a communications professor at Meredith College in North Carolina. "That's the tollgate."
As a young NBC reporter in New York in the 1970s, Spero remembers poking his head into Studio 8H at Rockefeller Center -- the home of "SNL" since the outset -- to see magic happen.
"It was like nothing we'd ever seen before," he told AFP. "It was so crisp and so original."
- The Palin effect -
For politicians, getting skewered on "SNL" is a rite of passage.
Sarah Palin's vice presidential bid in 2008 was forever haunted by Fey's scalpel-sharp impersonation of her "pitbull with lipstick" mannerisms.
But such is the show's impact that Palin couldn't complain -- in fact, she appeared as herself a few weeks later, in a hall-of-mirrors turn with her comedic alter ego.
Fans who cannot get enough can find all past episodes on Yahoo, although purists complain that more and more segments, like mock commercials, are pre-recorded rather than live.
"Every so often, you hear 'SNL' is at death's door ... (but) you keep coming back because you never know what topic they will tackle next," stand-up and improv comedian Andy Shaw said.