Based on talent and various style points, Michael Buble would have been a contender for the Rat Pack. His behavior off the stage, however, could get him into big trouble with Sinatra's crew.

"The longer I've done this the more sober I've got," he says in a phone interview. "I used to come off and have a nice scotch, but now I have to be a lot more disciplined. You almost have to be an athlete up there. You can't mess around too much. I want my voice to be strong, and I want my head to be in the right place."

Mr. Buble, who is engaged to Argentine actress/model Luisana Lopilato, says rather than carousing, "After [the show] sometimes I'll just go for a run, on a little treadmill, talk things over with my lighting guy, sound guy, talk about what we can make better for the next show. Have a little band meeting and talk about tempos. Just try to work on it. Then I go to my bus, and there's usually a line of a couple hundred people out there, and I sign stuff for them. It's a nice way to wind down."

Signing autographs and taking a run might not be Rat Pack protocol, but it's the kind of lifestyle that could keep the 34-year-old singer swinging for a lot more years to come.

Mr. Buble, who performs at the Petersen Events Center Wednesday, has been an unlikely success story, and it didn't happen overnight. The native of British Columbia started singing in nightclubs and talent contests when he was a teenager in the early '90s, then got his break when Grammy-winning producer David Foster saw him sing at a wedding and agreed, somewhat reluctantly, to produce his first album.

Sporting such standards as "Fever," "For Once in My Life" and "The Way You Look Tonight," it was a hit around the world but only a modest success in this country. He broke through a bit more with 2005's "It's Time," when his own song, "Home," hit the top of the Adult Contemporary charts.

"Call Me Irresponsible," leading with the single "Everything," made him a star in 2007. The album topped the Billboard charts and went double platinum in this country. Last fall, he kept all the rockers and hip-hoppers away from the top of the charts for two straight weeks with "Crazy Love," a fourth album that had him covering "Georgia" and "Stardust" along with the Eagles' "Heartache Tonight."

What can he bring to a song such as "Georgia" that so many legends have already covered?

"Whatever anyone who covered it tried to bring -- their own distinct personality," he says. "Whether I write or interpret, I'm trying to be as honest as I can. I'm trying to be in the moment and I hope if I believe enough that my audience will believe with me."

The most striking cover on "Crazy Love" is "Cry Me a River," which launches the album in grand Hollywood fashion.

"With the standards, in a lot of the songs what I'm really trying to do is interpret and bring them to life again, but what I'm really trying to do is conceptualize," he says. "I want a lot of the songs to be cinematic in a way. For 'Cry Me a River,' I wanted it to be really cinematic, really over the top and bombastic -- almost like a Bond theme. So I wrote that opening part for it and hoped we could incorporate it into the song and take it to a new place."

The singer has two writing credits on "Crazy Love," including on the first single "Haven't Met You Yet." He doesn't exactly put himself in the Lennon-McCartney category in terms of productivity.

"I take a long time. I don't really write something in a day. Usually, it's over about six months, and I don't write hundreds of songs and hope one is good. I usually start with a melody I think is really strong and I go from there and continue on that song and try to work it. If I don't feel like it's a hit, I don't go any further."

Despite the chart success with his own songs, he still considers himself more of an interpreter and doesn't expect to be filling future albums with originals.

"While it would be challenging for me," he says, "there's an audience of 25 million who bought these four records, and there are a lot of people wanting those standards to be there. And I don't make records for myself. I make records for other people, and as long as it brings those people joy, for me to cover songs from the great American songbook, that's what I'm going to do."

Last month, Mr. Buble got the world's stage when he turned up at the closing ceremonies of the Winter Olympics in Vancouver, peeling off a Canadian mountie uniform to do a white-tux version of "Maple Leaf Forever."

He was honored to represent his country, he says, and, being a hockey fan, was thrilled by Penguins captain Sidney Crosby scoring the winning goal for Canada.

"Most of his career, obviously, I've known how incredible he is," he says. "I only wish he played for my hometown team. I will now forever be a huge Sidney Crosby fan. He stepped up when it was time, and our whole country went crazy. We're really proud of him."

Just as the Pens star does, though, the singer feels like he has a lot more to accomplish, and he doesn't plan to cruise on his past success.

"I'm more confident in what I'm doing, but I have to believe that you're only as good as your last record -- especially in this business now. It's a volatile business and it's harder than ever to sell records. I just don't think you can pat yourself on the back too much. While I appreciate the moment and smell the roses, each time out I put pressure on myself -- you gotta be better.

"This record took longer than any of the previous ones and the next one will probably take even longer. It's gotta be right."

Critics Andrew Druckenbrod and Scott Mervis talk about music on "The Beat," available exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.