Fans and critics have been asking Linda Perry the obvious question: Why did she leave 4 Non Blondes at the peak of the pop-rock band’s popularity?

One listen to Perry’s absorbing debut solo album, “In Flight” (Interscope), and they will be pondering the more reality-based question: Why was she in 4 Non Blondes in the first place?

That sentiment brings an uproarious laugh from the dauntless singer-songwriter.

“That was the first band I’ve ever been in,” Perry said recently from her San Francisco home. “(Bassist) Christa (Hillhouse) was in 18 bands, (drummer) Dawn (Richardson) was in 15 and (guitarist) Roger (Rocha) was in 12. Before 4 Non Blondes, I just traveled around San Francisco with my guitar and showed up at places and asked if I could play.

“I wrote my own songs at my own convenience, rehearsed in my bedroom or in the bathroom, whenever I wanted. There was no schedule. I was actually very happy and content doing that, and I started getting recognition in the city. Then all of a sudden, this band came and asked if I wanted to be in it, and I thought it seemed fun. So, ‘what the hell, why not?’ ”

It was fun … while it lasted.

The quartet’s debut album, “Bigger, Better, Faster, More!” (produced by David Tickle), stretched rock’s boundaries with a fusion of acoustic folk, blues, funk and electric rock. It wasn’t embraced immediately; in fact, it sold only 8,000 copies within 12 months after its May 1992 release.

Then a Las Vegas disc jockey latched onto the nervy, slow-burning track “What’s Up,” highlighted by Perry’s powerhouse voice, and it snowballed from there. Before they knew it, they had a gold-plated single, the album sold more than 5 million worldwide and they were playing at the MTV Video Music Awards, with Perry’s dreadlocked mane and funky hats at centerstage.

Somewhere along the line, things changed. It became less fun and more of a pain for Perry.

“When I first joined, I didn’t play any of my songs; I didn’t bring any songs in,” she said. “I just sang their songs that they wrote. I was like this punk, a complete freak the whole time. And then they were about to kick me out because I wasn’t taking it serious, never showing up to practice, always late to shows.”

Perry said she heeded their warning and brought in songs she had been working on during sessions for their follow-up album, but by then it was too late.

“I decided to leave because they wanted to stay with this pop-rock thing,” Perry said. “I thought, ‘It’s time to move on, you guys, we did it already. Let’s go do something different.’ They were very influenced by the commercialism, safe environment, money in the pocket, people-are- going-to-see-us-play-because-we-write-pop- songs thing. I wasn’t like that.”

Now on her own, Perry took time off and immersed herself in Pink Floyd’s “The Dark Side of the Moon,” listening to it daily. She became obsessed with the legendary album’s song-to-song mood swings. Not so surprisingly, she thanks Pink Floyd for “Dark Side” in the liner notes of “In Flight.”

“I was completely influenced by that album, and I’m not afraid to admit it,” she said. ” ‘In Flight’ isn’t a mini-concept album, I call it more of an audio diary, where I’m expressing my feelings. Yes, sometimes I get (screwed) up and sometimes I’m really happy and I get a little depressed. It’s about a person going through these emotions, which are very normal and natural.”

“In Flight” creates a sonic atmosphere for visualization in the mind, Perry said, and it’s apparent from the opening cut, “In My Dreams,” and on through to the closing title track. “The last song is saying, ‘Hey, everything you’ve just heard right now, this is what I am, this is what I’m going through, and everything’s going to be okay,’ ” Perry said. “If there’s a concept, that’s what it is.”

In between, tracks such as “Freeway,” “Fill Me Up” and Perry’s eminent pairing with Grace Slick on “Knock Me Out” form a palatable package.

Just getting Slick on her side was well worth the ride.

“Grace Slick is an overwhelming character,” Perry said. “I love her. She has this really powerful presence that you feel like a little mangy dog that runs around her and wags its tail. That’s how I felt around her.

“I begged and groveled and pleaded, ‘Please come down and just listen to my record and I guarantee you’ll like it. I know you will.’ I heard she doesn’t like any female musicians except for like Chrissie Hynde and Patti Smith. She hates all these newcomers, calls them ‘wimpy girl singers.’ I called her and I said, ‘I’m not a wimpy girl singer.’

“She came down to the studio and I played it to her, and I was sitting right there and I was completely stressed out and nervous. I’m thinking ‘What if she hates my record?’ She ended up loving it and said, ‘What do you want me to do?’ I said, ‘This is the song I want you to sing on,’ and she kind of wrote her own lyrics and went for it.

“She’s so cool. I think it’s more of a deal to me than I think people might get. I don’t know how to explain it. I just feel like I got a pat on the back from a peer, that I must be doing something right.”

BWF (before we forget): Check out Perry on the Web @