If not for his co-starring appearance with Keanu Reeves earlier this year in “Bill & Ted Face the Music,” playing the now-adult Bill AKA William S. Preston Esq., even Alex Winter’s fans would have thought he’d retired from acting. Apart from some sporadic voice work in series TV, he essentially had. His last on-camera appearance in a feature film was in 2013’s “Grand Piano,” and he had only two previous acting gigs since “Bill & Ted’s Bogus Journey” in 1991.

But by then, Winter had already started working behind the camera, directing commercials, some Red Hot Chili Peppers videos, and the feature films “Freaked” and “Fever,” and he became interested in making both short and feature-length documentaries.

His newest, “Zappa,” is a wide-ranging and personal look at the life of the late music icon Frank Zappa. Winter, 55, a longtime Zappa fan who regrets that he never got to see him play live, spoke about the film from his home in Los Angeles.

Q: “Zappa” is your second feature documentary this year, after “Showbiz Kids.” But you’ve been making them since “Downloaded” in 2013. What got you into this genre?
A: I came into docs kind of sideways through a narrative project I was doing on the Napster story. I had gotten the rights to (Napster creator) Shawn Fanning’s life story. I had it set up at a major studio, but it went into turnaround, so it wasn’t going to happen. But it was a story that I felt very committed to telling, and it later occurred to me to make it as a doc. I went out and pitched it and sold it right away. That was “Downloaded,” and while making it, I was struck by the documentary form and how you can get a character in such a nuanced way, so I kept going.

Q: Why Frank Zappa, and why now?
A: I’ve been a big fan of Zappa, and not just of his music, but of who he was culturally, and the impact that he had culturally. It’s very rare to find an artist as unique and as committed as Zappa was to his art, and who was equally engaged with the times around him. So, he was a really interesting doc subject in that way. (My producing partner) Glen Zipper and I were finishing up a film together, we were looking at what to do next, and were scratching our heads wondering why a documentary about Zappa had never been done. That began our journey. That was when we approached (his widow) Gail Zappa about it. That was six years ago.

Q: Did you have much input from Gail and was there any problem with you getting final cut?
A: I had approval from the family, and I was very close with Gail in that last year that she was alive (she died in 2015). I filmed her at the house quite a bit, talked to her a lot about what I was doing, and the way we were navigating the story. But I wouldn’t have even started the film without final cut. I said to Gail from the very beginning that the only way to preserve the integrity of the film was if it was an independent film being made by us, and not something that would be perceived as a two-hour commercial for Zappa, Inc.

Q: One of the most amazing things about the film is that we get to see the inside of Frank’s archives, also known as “the vault.” Do you recall your first time stepping inside?
A: It was somewhat mythical. I knew that a vault existed; I had seen some YouTube clips of Frank walking around down there. But you don’t ever really know to what degree the stuff is actual. Gail said in order to tell the type of story you’re saying you want to tell, which is a warm and intimate exploration of him, you’re going to need access to the vault. So, I remember a kind of combination of elation and dismay when I went down there. It was amazing and vast, but I distinctly smelled vinegar down there and I realized that some of the older film material was in danger of deterioration, so we set out to preserve it. We realized it was going to cost a lot, so we did a Kickstarter campaign. We raised about a million dollars, and we preserved the endangered media.

Q: Is that where you found all of the footage of Frank talking about himself and his music?
A: Yes. After we began to pull in the media, we realized not only what a wealth of content we had of him in first person, but more importantly how honest that content was. There are a lot of interviews of Frank out there in the world, but a lot of them are very superficial. He’s super entertaining and irreverent, but he’s not divulging any of his interior life. We were discovering that the content we had was very intimate, and that he was absolutely sharing himself, and that there was lots of it, spread across time. So that drove how we built the narrative.

Q: It really is a narrative documentary, one that tells a story. With all of that material, how did you decide what to keep in and what to leave out?
A: I have a narrative background, so I’m used to building things that have a specific kind of classical structure to them. And (my editor) Mike Nichols has been at this for a while. What I pitched to Gail at the very beginning was that rather than try to swallow up all of Frank’s life whole, with every single detail, going album to album with every biographical detail, we wanted to tell a story. The story we wanted to tell was about the inner life of this man, and the consequences he faced for choosing the artistic life that he chose, and the battles that he would have to fight because of the commitments he made to that kind of life. So, any material that we had that didn’t serve that story or move the story forward, we just didn’t use. There’s a lot more of it. You could make a 10-part series out of Zappa’s world very easily. But that was never my interest.

“Zappa” premieres in select theaters and on VOD on Nov. 27.
Ed Symkus can be reached at esymkus@rcn.com.