OYSTER BAY, N.Y. >> “You see that boat out there?” Billy Joel asked, pointing beyond the dock and the helicopter pad in his backyard to Oyster Bay Harbor. “That’s an oyster boat — a dredge. I worked on one of those, when I was 17 or 18. I used to look up at these big houses and say, ‘You rich bastards!’ I remember looking at this house and cursing. Now I own the place.”

Early one Friday afternoon, Joel, 69, was smoking a small cigar on one of the front lawns of his 26-acre manor, cleverly dubbed Middle Sea, at the tip of Centre Island, a peninsula on the North Shore of Long Island. The estate was built by a railroad baron, George Bullock, some hundred years ago. Joel bought it in 2002 from a big shot at Goldman Sachs.

“This is Gatsby country,” he said, as three rescue dogs romped around a long table, which sat beneath a trellis. Nearby, a nanny looked after his 9-month-old daughter, Remy Anne, his second child with his fourth wife, Alexis Roderick.

Joel remains one of the most successful artists in the music industry, even though he has not released an album of new pop songs since 1993 and tours on what he calls a “pussycat schedule.” He has had a monthly residency at Madison Square Garden since January 2014; on July 18, two days before our interview, he played his 100th ever show there. Each concert has sold out, which is a level of success the Garden’s other franchises can only envy. “It’s bigger now than it was at the height of my recording career,” Joel said, more puzzled than boastful.

Joel identifies as a smartass: “I rub people the wrong way, with that stupid Long Island chip on my shoulder.” It is his nature to be blunt, unapologetic and self-mocking. These are edited excerpts from the conversation.

Question: Which is worse, having your picture taken or talking about yourself?

Answer: Taking pictures is painful. I don’t look like a rock star, which I don’t mind.

Q: Do you still sing your songs in their original key or do you lower them?

A: Some of them we drop a whole step, some we drop a half step and some are still in the original keys. When I get to a point where I got to go more than a whole step down, it’s probably time to hang it up. I find myself onstage thinking: This is a young man’s job. What am I doing?

Q: This summer is the 25th anniversary of your last pop album, “River of Dreams.” Did you dislike it?

A: In the early ’90s, I started listening to the Beethoven symphonies and I said: “I haven’t done (expletive). This is great.” I was, let’s see, 44 years old. It was time to do something else. I wasn’t going to make albums just because the record company had a contract on me.

Q: A contract “on” you? Like the Mafia?

A: That’s how I see it! They own the recordings, so I’m writing for them. I saw it happening with Elton (John), other big-name artists. The last album didn’t sell as much, got to put out another album, and they end up diluting their legacy by putting out albums that are no longer good. With “River of Dreams,” I took myself out with a No. 1 album.

Q: But when you’re a songwriter, melodies don’t just stop coming into your head.

A: No.

Q: So when you wake up in the morning with a melody in your head, what do you do?

A: I write. I continue to write the music. I develop it, I do expositions, variations. But I haven’t recorded it. I haven’t even notated it. It’s all here (taps his head).

Q: So you don’t care if anyone else ever hears it?

A: I’ve had more fame than I deserve. I thought I was going to make a living and it turned out I got a hundred shows at Madison Square Garden, Kennedy (Center) Honors, the Gershwin (Prize), da da da. It’s pretty cool, but I’m not Beethoven.

Q: You recently described your time at the Betty Ford Clinic in 2005 as one of the most important times in your life. Why was it important?

A: That was the only time I actually went to rehab. I tried, a couple years before that, to go to this place in Connecticut, Silver Hill, but the media found out and there were reporters all over this campus. I was there for two days, nobody could get anything done, so I left. The next time, I went to Betty Ford in the desert. Felt like I was in Alcatraz or something. For 30 days, you can’t have a drink. I had an epiphany: I don’t have to drink like I was drinking. But I’m not an AA guy, not a 12-step guy.

Q: Some problem drinkers stop drinking but are then able to drink moderately. But in AA, that’s not allowed. Is that why you don’t like it?

A: Yeah, I have a problem with the absolutism of that. “I’m an alcoholic, I’ll never be cured.” I said, “Wait a minute, there’s something called willpower.” I don’t buy into the higher-power thing. The closest thing I have to religion is music. I worship at the altar of Beethoven.

Q: You have two young daughters. Did you have any misgivings about being an older dad?

A: Yeah. I know there’s a finite amount of time I have left to be with them. But because of the nature of what I do, I may get to spend more time with my children than most people do. I spent most of my life traveling like Willy Loman. I’m a homebody now. When they start school full-time, somebody’s got to drive them there. I didn’t have a dad — he wasn’t around. Being a father is very important to me. I want to make sure I leave my imprint with them.

Q: At the Garden, they raised a banner to commemorate your 100th show. What are the odds we’ll see one for your 200th?

A: Don’t bet the farm. I’m still exhausted from the other night, which didn’t used to happen. I don’t think I’ll have the physical wherewithal to do it five years from now. And if I can’t do it as well as I want to, I’ll take myself out of the lineup. I love the game too much to not play it well.

Q: So if you want to see the show, see it soon.

A: You can say that, but I’m not going to. I mean, these guys who do farewell tours — it’s funny, the farewell tour goes on for 10 years. The Who has had, what, like 20 farewell tours? I keep getting asked, “What’s the secret of your longevity?” I say, “I haven’t died.”

Q: That’s good advice: Stay alive.

A: Yeah, don’t die. It worked for me.