What were your expectations going into the pilot?

A show about the Mob was really a risky thing. I thought it was a long shot that it would run for a long time, just because there hadn’t been anything like that. I was immediately impressed by the cast. It was really hard to tell from the pilot what the show would be. Was it going to be a spoof? Because there was a lot of funny stuff in the pilot. We didn’t really know until we started shooting the first season. I was, like, “Wow, we’re onto something good.”

Did you develop a familial relationship with Gandolfini?

Absolutely. Doing that show was like going down to the corner and hanging out with your friends every day. That’s a very rare thing. He was such a tremendous talent and such a good actor, so committed, passionate and kind.

How do you feel about “The Many Saints of Newark,” the coming prequel movie to “The Sopranos”?

It’s going to focus on Christopher’s dad. I like that it’s going in that direction rather than something right after the last episode ended, picking up those pieces. Doing something that has the DNA of the show but is its own thing is really smart. I’m sure it’s going to be great.

How do you look at the other series you’ve done that haven’t lasted as long as “The Sopranos,” like “Life on Mars” and “Detroit 1-8-7”?

You just need to take each job as it comes. If you say, “I’ve got to wait for the next ‘Sopranos,’” you may be waiting forever. It’s such a difficult business to have longevity in, to be frank. You’ve got to find what you’re passionate about, and if you’re not getting the roles on TV and in movies you want, then try to do it yourself — independent film, theater and writing books.

Your novel is set in the New York City of the ’70s. Do you feel that city is gone?

I do. I didn’t start spending a lot of time in Manhattan until 1983, but in the ’70s I’d go to the city with my family to see a show or go to Rockefeller Center. I have a lot of nostalgia for the movies of the time, and I was always drawn to that period. I mean, everything changes, and New York City has changed as much as everywhere else. It’s hard to know if that feeling of nostalgia is for your youth or the city.