A delovely evening of Porter treasures

Everybody loves the Great American Songbook. How could they not? All those marvelous lyrics, simmering with inner rhymes and double-entendres, all the soaring melodies, rich harmonies and pulsing rhythms.

Few performers understand the full extent of that treasure musical trove as well as the husband-wife team of singer Karen Benjamin and pianist Alan Chapman. Fewer yet comprehend the importance of looking beyond the great classics to find the extraordinary material that has either been dimmed by the passage of time, or that never made it into the spotlight.

Benjamin, a gifted soprano who starred in the L.A. production of “Phantom of the Opera,” and Chapman, a radio host on KUSC-FM (91.5), have always included offbeat items in their cabaret duo act. But recently they have embarked on a series of fascinating concerts illuminating the lives and the music of great American songwriters, with Chapman offering insightful commentary and Benjamin applying her versatile voice to familiar material as well as to songs that have not seen the light of day since they were written.

On Thursday at Steinway Hall in West Los Angeles, they immersed themselves in the musical and lyrical sophistication of Cole Porter. There were plenty of familiar items: Benjamin’s gorgeous rendering of “In the Still of the Night,” her sly take on “My Heart Belongs to Daddy” and an atmosphere-rich version of “Love for Sale.” Together, the duo had fun with “Let’s Do It,” “Let’s Misbehave” and “Anything Goes,” and Chapman revived the raunchy wit of “Brush Up Your Shakespeare.”

But the real heart of the program traced to the offbeat tunes: the astonishingly rich melodic and harmonic palette in the odd song “Ah Fong Lo”; the suggestiveness of the lyrics for “But in the Morning, No” (which manages to find sexual innuendo in double-entry bookkeeping); the sweet tune “My Broth of a Boy”; the hilarity of “Where Would You Get Your Coat?” and “Why Marry Them?”

What emerged from this colorful tapestry of song, enhanced by Chapman’s intriguing anecdotes, was a sense of the length and breadth of Porter’s talent. And if there’s any justice in the world, it will eventually find its way to a CD, providing a valuable and immensely entertaining chronicle of the work of one of the most vital contributors to the Great American Songbook.