POP MUSIC REVIEWS : 2 Routes on a Tour of American Songbook : Mel Torme won the crowd with his rhythmic style; Maureen McGovern brought her expansive range and clarity to the Celebrity Theatre show.

Just when it seemed that the rock ‘n’ roll generation had grown up without a notion of who Cole Porter was, let alone Irving Gordon, along comes Natalie Cole with “Unforgettable,” and upstart pianist-singer Harry Connick Jr. creates a sensation crooning Tin Pan Alley tunes backed by a big band. Suddenly, once again, the Great American Songbook lives.

Singers Mel Torme and Maureen McGovern, neither of whom ever neglected the tradition, paid tribute to it Sunday at the Celebrity Theatre, covering nearly a century of popular tunes. Backed by a 16-piece band, the two worked different styles, alone and together, for a satisfying tour down memory lane.

McGovern, who opened the show, brought her expansive range and clarity to a set loaded with jazz-inspired numbers. Her voice was glossy and clean in the upper reaches, and she imparted a vibrato-less purity to sustained tones.

Her scat on “Little Jazz Bird” took on instrumental qualities, especially in harmony or when trading lines with the flute. She traded measures with trumpeter Ron Barrows during Sam Coslow’s “Mr. Paganini (If You Can’t Sing It, You’ll Have to Swing It)” in tones that brought to mind trumpeter Maynard Ferguson’s high-end enthusiasm.

McGovern carried her set with the beauty of her tone; Torme--whose voice remains warm, if not focused--won the crowd with his rhythmic style. He came out scatting on a medley of “Just One of Those Things” and “On Green Dolphin Street,” messing with the rhythms and sometimes hanging behind the beat for dramatic effect.

He balanced a mellow tone against a quintet of clarinets during Hoagy Carmichael’s “Star Dust,” after declaring that the tune is on the “top of the first page” of that Great American Songbook.

In an attempt to keep the book current, Torme sang Neil Sedaka’s “Love Will Keep Us Together” and Billy Joel’s “New York State of Mind.” Explaining how he had searched today’s pop music looking for other things to include, but came away empty-handed, he offered his own rap, something he called “Dilemma.” Sample line:

“If I start rappin’ at my age

the audience would stand and boo me off the stage.”

Highlights of Torme’s set were his arrangements for the band (he wrote all but three), including a spirited “It Don’t Mean a Thing (If It Ain’t Got That Swing)” and “More Than You Know,” which featured a haunting muted-trumpet passage. The singer also paid tribute to Marty Paich, with Paich’s arrangement of “Blues in the Night.”

Torme and McGovern combined for a long medley of tunes from Rodgers and Hart, again arranged by Torme, that featured “I Wish I Were in Love Again” and “Mountain Greenery,” a number long associated with Torme.

Though it’s unfair to criticize a two-hour program of American songs for what it failed to include, a few of the numbers that were included certainly seemed expendable. McGovern’s trademark “The Morning After (Theme From the Poseidon Adventure)” seemed somehow out of place.

And Torme’s “Hawaiian War Chant,” done as a tribute to his late friend (and the subject of a Torme biography) Buddy Rich, with the singer taking a turn at the traps, was certainly good for nostalgia but hardly of the quality of the rest of the program.