Sometimes, when you taste something particularly flavorful, you want to calculate the ingredients in hopes of duplicating the recipe. But sometimes you're best off just savoring the taste.

If you've heard about the top-of-the-pops success of singer Michael Buble - who swings with a big band and croons ballads of an earlier era and newer ones dressed in vintage attire - it would be understandable if you bear some cynicism about this retro formula.

But the evidence is in from the first of two nights by Buble and band at Minneapolis' Orpheum Theatre, and it's almost all favorable. If Buble's an opportunistic imitator of a swing-era singer, well, it's a pretty convincing act. He treated Friday's full house to an enthusiastic and affectionate 90-minute show, one clearly inspired by the spirit of Sinatra and his wise-cracking Rat Pack, but bearing enough modern trappings to not seem a discomfiting flashback.

Sharing the stage with a 13-man backing band - including an eight-piece horn section - Buble was a disarmingly unpretentious frontman who seems to truly enjoy performing. And it should be noted that the Vancouver native takes a tip from the man who set the template for this style of cosmo cocktail party, Frank Sinatra, in that he seems to respect his talented bandmates. On Friday, Buble always seemed excited about sharing the spotlight with the jazz musicians around him and, as he said, "continuing the legacy of this great music."

Granted, one wouldn'tmistake Buble for one of the geniuses of vocal interpretation like Ella Fitzgerald. But he knows how to fit his slightly husky baritone into some imaginative arrangements like a meringue-fied version of Henry Mancini and Johnny Mercer's "It Had Better Be Tonight" or a cool and smoky take on Otis Redding's "Try a Little Tenderness." And his boyish charm isn't burdened by arrogance, making him a delightful companion throughout the exuberant concert.

Buble and band grew increasingly poppy in their delivery toward the end of the show. While the songs were among his most popular, they were also the ones that gave his talented musicians the least to do. Buble was at his best when he appeared lost in his love of jazz, as when he was swept away in a cappella scatting leading into "Call Me Irresponsible." Perhaps Buble's popularity will wane over the years, but, if he trusts his jazz impulses, it should be a fine career.