Any doubts that Al Jarreau was born to sing are quickly dispensed with by a simple conversation with the man —— he is incapable of holding forth on the topic of music without dipping into the subject at hand.

Not 10 minutes into a phone interview, Jarreau is scatting through a passage from a classic bop song of the 1960s, pointing out how the chord changes were lifted from an even earlier swing standard. ("I better not show up in jazz heaven," he laughs after pointing out the similarity in the songs. "They'll be mad at me and they'll be kicking my butt!")

Any suspicions that Jarreau, who performs Sunday at Pala Casino, is running out of steam in his mid-60s are dispelled by both the vigor of his new album ("Accentuate the Positive") and his enthusiasm in talking about it and future projects.

" 'Accentuate the Positive' was a long time coming, and I'm paying a debt I've had for a long time to do a straight-ahead jazz project, with material that comes from that era, lots of it, and comes from the great American songbook," Jarreau said by phone from his Southern California home, where he said the rains were busy flooding his back yard.

"I've been talking about this record for closer to 20 years than 15, and I'm just slow getting there. I wanted to do material that I hadn't recorded ever before, but which is responsible in many ways for my being the singer folks have known since 1975. These songs were my classroom, they were my academy."

Although he's best known for his R&B and pop hits from the mid-1970s through the '80s (and casual fans may remember him for the theme song from the hit TV show "Moonlighting," Jarreau began his professional life as a straight-ahead jazz singer while attending the University of Iowa in the early 1960s.

"I was 23 or 24. I was a student, and that was my main vocation, but singing was my love," Jarreau said.

He and some friends had a weekend gig at a local club in Cedar Rapids called the Tender Trap.

Jarreau and his bandmates even got to the point of renting out a studio and cutting some songs. Those tracks later ended up being released as the album "1965" by an independent record label, an album Jarreau long disassociated himself from but is now coming to appreciate.

"It was not intended to be for public consumption," he explained. "That record was done just for us to enjoy the music we were making."

By the time "1965" was released, it was 1975 and Jarreau was an R&B star for Warner Bros. He said that record caused him grief with Warner Bros. and he never got paid a penny for it. Still, Jarreau said of the unauthorized release, "In more recent years, it has occurred to me that that period of my life has not been documented." And he also allowed that "the performances were pretty polished performances. … I'm glad that record is out there."

His new record is on Verve Records and getting a lot of positive press —— and Jarreau is staying busy touring. Yet he admits that the more narrowly focused formats of contemporary radio don't have room for a genre-defying artist such as himself.

"Airplay is so confined and limited. It seems like we're in a world of choices, and there's a real freedom in America for what you want to listen to. But there isn't. It's all decided by a handful" of executives.

So how does he explain his own ongoing success?

"I've refused to go away!" he laughs raucously, then adds, "I'm an ex-cross-country guy, so I know about long-distance running and being lonely. And I wish I had done a little high school wrestling, because it gives you grit. I love what I do. I would do it for free. I've done it for free.

"But for sure, you can't get rid of me. Maybe I'm appreciated for some degree for that!"

Jarreau also said he enjoyed seeing the popularity of Norah Jones.

"The amazing success she has had is representative of America's need for a little more thoughtful music, a little more quiet music; music that has more than three chords in it.

"I love that people are coming back to it."

As for his own future, Jarreau said he wants to tackle a big-band album yet, and one other style he's yet to take on.

"I owe the world a Christmas album," he said.