Style, it might be argued, is the sum of a musician's reflexes: the melodic contours, harmonic turns, rhythms and verbal patterns that come most naturally. Elvis Costello is determined to refute that argument. Whenever he grows secure in a style, he sets it aside and seeks out another one, fighting his own reflexes to a draw.
His new album, North (Deutsche Grammophon), is his latest battle with himself. Last year he reunited with most of his crafty late-1970's band to speed up and rock out on When I Was Cruel (Island); now he has veered to the opposite extreme, singing slow, sustained ballads. At Town Hall on Monday night (he has a second concert there tonight), accompanied only by Steve Nieve on piano, Mr. Costello retrofitted his old songs with his latest approach while he unveiled new ones. He made up in drama what he had sacrificed in decibels.
The songs from North turn Mr. Costello's usual gambits inside out. The album has a story line about an old romance collapsing and a new one beginning (although the title song, which is available only on the Internet, is more playful, a tribute to Canada). On the album the lyrics replace Mr. Costello's usual rush of images and wordplay with brief, emotionally direct verses: "Maybe this is the love song that I refused to / Write her when I loved her like I used to."
While the words aspire to transparency, the music grows complex, as if Mr. Costello soaked up as many convolutions as he could from his 1998 collaboration with Burt Bacharach, Painted From Memory (Mercury), then set out to bend and fold them further. He sounds as if he has been studying Cole Porter, Randy Newman, Paul Simon, Stephen Sondheim, Chopin and Schubert, too. The North album features Mr. Costello's own arrangements for strings and horns, but onstage he put down his guitar for the new songs, letting Mr. Nieve provide pastel jazz harmonies and pristine quasi-classical embellishment.
In the past a typical Costello melody has taken clear, stepwise motions up and down the scale, while using symmetry to make the audacious lyrics more approachable. But his new tunes rarely go very far without taking a leap to an unlikely note. They also use harmonic nuances to paint the lyrics, with rising or falling chords to match mood shifts and chromatic tensions giving way to reassuring major-chord resolutions.
Mr. Costello chose older songs, like "Shot With His Own Gun," "All the Rage," "Rocking Horse Road" and "Almost Blue," that are full of betrayals and bitter aftermaths. As he sang them, Mr. Costello reveled in dynamics: a desperate crescendo followed by a brooding hush, a shout leading to a pained reconsideration. He often moved away from the microphone, letting his voice be heard unadorned.
Mr. Costello hasn't made his songs easy on himself. He's at the limits of his vocal instrument in his new ones, trying to use the strain in his voice to suggest yearning. Another singer might be more comfortable with this music. But Mr. Costello would clearly rather find comfort in romance than in songwriting.