If you pitched a weekly sketch comedy series with elements like raunchy Muppets and a cast member who does an impersonation of the president without looking much like him, would you expect that show to stay on the air for 40 years? From unorthodox beginnings, “Saturday Night Live” has grown into an indelible part of the popular culture.

There’s still one guiding force orchestrating every cold open, every off-kilter sketch in the last 10 minutes and every “Weekend Update.” That’s Lorne Michaels, who created the program and has supervised every episode excepting a notorious five-season stretch in the 1980s. He talked to Variety about what viewers will see when they tune in to the 40th anniversary special Feb. 15 on NBC, maintaining a vision for the show in the face of armchair critics, and “SNL’s” future:

How will this special compare to past anniversary celebrations?

More live performance, not so much clips. All the generations are coming, and so there’s a little bit of a mash-up between different casts, people who have never really worked together before. I think we’re going to do “The Californians,” but we’ll do it with different people. We will also have some live music performances: Paul McCartney, Kanye West, Paul Simon, two or three other big numbers. Everything is subject to change. … Most (cast members) from over the years are coming back, and an enormous number of people who hosted. It’s like any other reunion. It’s both (a feeling of) dread and “You know what? This is happening.”

You have longtime fans who expect something unconventional, a crowd who knows “SNL” as entertainment, and a new group watching via streaming and viral videos. Which aud do you have in mind?

I think we get the baby-boomers and high numbers of people between 18 and 34. We are still the No. 1-rated show on the air (at that time). I think people understand the show after this many years. They know there’s going to be something for them.

People are excited about Eddie Murphy coming back for the special, but what place do you think the Dick Ebersol and Jean Doumanian years (in 1980-85, when Michaels wasn’t at the helm) have in the show’s history?

It was a really important time, and Eddie Murphy may be the biggest star ever to come out of here. I think we’ll pay a huge amount of respect to it, and a lot of the other people from that era. … The show went on, and I wasn’t doing it. There were an enormous amount of good things that came out of the show then.

Social media is a platform for “SNL” critics. How do you balance what those voices want and your own vision for the show?

It comes down to the 400 people at dress rehearsal. You are not in an editing room cherry picking. It’s all of a piece, and you can’t make that constant change. It’s not just sitting down and targeting a demo. I think it’s about a certain taste and, hopefully, a certain level of intelligence.

If NBC came to you and said, “This is a franchise just like ‘The Tonight Show’ and we want to figure out a way to keep it going,” would you be interested?

I would not be happy to see it go off the air, and I would also expect at some fundamental level that they would leave it as is. It’s a very expensive show to do, but it’s necessary to get to the next step.

Any thought about which of your many protégés would be up to the task?

There are so many people here who do so many different things. When the time comes, when it just makes sense to make the decision, that’s when we will make it.