Diana Krall at Tangelwood

Diana Krall's onstage persona has been rather chilly at times - her small talk banal, her introduction of musicians limited, and at times, it even seemed that she would just as soon rush through her set as entertain her audience.

However, if the set she performed at Tanglwood on July 4 was any sort of indication she has come into her own as a performer and jazz musician. Her ninety minute set was supported by a fine backing trio, and supplemented at times by an orchestra, conducted by the pianist Alan Broadbent.

Miss Krall (should I say Mrs. Costello?) charmed the audience with her self-deprecating stories of her two children, her marriage to a rock star, and her childhood growing up on Vancouver Island. Her musical selections were equally beguiling, opening with her now traditional "I Love Being Here With You", and including several Brazilian-tinged tracks from her latest album, Quiet Nights.

Her singing skills have been well documented, but it takes a concert setting to see just how accomplished a pianist Ms. Krall has become. "Deed I Do" and "Cheek to Cheek" were exception, showing her sense of timing, rhythm and speed. The band was cooking so hot on the latter, that Ms. Krall almost forgot to sing. "Frim-Fram Sauce" in particular was a joy, with Ms. Krall allowing herself some vocal growling and boogie-woogie piano.

Her band - Anthony Wilson on guitar, Robert Hurst on bass, and Jeff Hamilton on drums - is a perfect foil for her playing. When she chooses to be soft, or play minimalistically, Hamilton is there with his brushwork. When its time to kick it up, Hurst and Wilson are ready to raise the stakes, pushing Ms. Krall along and taking their solos with glee.

By the time Ms. Krall had encored with a string soaked "The Look of Love", there were few disbelievers among the 15,000 fans in the shed and lawn of bucolic Tangelwood. How about an Elvis Costello-Diana Krall double bill next year? Or maybe a special taping of Elvis' talk show "Spectacle" using Tanglewood as a stage. Food for thought.