NEW YORK – When Michael Feinstein begins a five-night engagement Tuesday evening, performing Frank Sinatra songs with a 17-piece big band in the ballroom at Feinstein's at Loews Regency, the Manhattan supper club bearing his name will open its 10th-anniversary season.

The date coincides with the release of his 24th album, The Sinatra Project (Concord), a record that differs from all other tributes to Ol' Blue Eyes in its fusion of Mr. Feinstein's passions for performing and musical archaeology.

Before he took to the stage, Mr. Feinstein, who turns 52 on Sunday, spent seven years as Ira Gershwin's assistant and amassed an invaluable trove of Gershwiniana that is now housed at the Library of Congress. His cabaret performances and four annual concerts at Zankel Hall include fascinating obscurities he has dug up from the past, alternate lyrics and little-known verses from familiar standards.

Recorded mostly in Los Angeles at Capitol Records' Studio A, where Sinatra made his classic concept albums, The Sinatra Project is a scrupulous effort to re-create the sound and style of the late-'50s Capitol albums Sinatra recorded with arranger- conductors such as Nelson Riddle and Billy May. Several of the arrangements by the gifted retro-bandleader Bill Elliott might be described as aural trompe l'oeil.

"The concept of the album followed a circuitous path," Mr. Feinstein explains in the piano room of his Upper East Side townhouse. "It began as a tribute to the Greatest Generation without the hackneyed material. Then it became songs Sinatra might have sung but never did, then love songs, and finally songs he did perform but with different arrangements, so that it wouldn't sound like I was trying to copy him."

More than two decades ago, when Mr. Feinstein was starting out as an intimate piano-bar performer specializing in Gershwin, the notion that he would some day record a swinging big-band album would have seemed unlikely. Since then he has evolved into a stand-up concert entertainer whose singing has grown in stamina, vocal range and rhythmic freedom. Nowadays he plays 150 dates a year, mostly in large halls.

As he has stepped out from behind the piano, he has also developed into a polished storyteller and celebrity mimic. He is one of the last all-around traditional entertainers in a post- vaudeville tradition that stretches from Al Jolson to Billy Joel.

When not touring, Mr. Feinstein holes up in the basement studios of his homes in New York and Los Angeles and digitizes his ever- expanding sound archive. Its ultimate destination is a $160 million performing arts center in Carmel, Ind., to be completed in 2010. An attached museum, offered rent free, will be the national headquarters of the Feinstein Foundation for the Education and Preservation of the Great American Songbook and will include all his memorabilia and manuscripts.

Stephen Holden,

The New York Times