Principal in Cleveland, regular at Happy Dog

So ingratiating, stylish and historically iconic is the flute that it's hard to imagine why the instrument claims the spotlight so infrequently: Joshua Smith's flute concert Tuesday is a once-every-two-seasons occasion for the Philadelphia Chamber Music Society.

Educated at the Curtis Institute and ensconced in the Cleveland Orchestra's principal flute position for 21 years (he was hired at age 20), Smith now appears to be pursuing a solo career: He's recording Bach for the Delos label and is looking more like a movie star than a classical musician in his latest publicity photos.

Yet Smith demurs. "I don't see it as a real possibility," he said by phone from Cleveland. "Violinists and pianists have much better chances at solo careers. They have Beethoven and Brahms sonatas and all of this wonderful stuff that people want to hear. But with the flute, you can only build so many recital tours with the repertoire that we have."

Smith is proud of the program he will play with pianist Christina Dahl Tuesday at the American Philosophical Society. Titled "Day and Night, I Call Only Love," its succession of Schubert, Schumann, Reinecke, and Carter has literary underpinnings related to unrequited love.

The concept's connection is obvious with Introduction and Variations on Trockne Blümen drawn from Schubert's song cycle Die Schöne Mullerin and the paragon of romantic rejection that is its protagonist. Not so obvious is Scrivo in vento by arch-modernist Carter. But it's based on a Petrarch poem about unrequited love, and in any case, says Smith, it's "a manic piece . . . introspective, doubtful, wandering and with complete outbursts of chest-beating. It's like listening to somebody's crazy thoughts . . . ."

"I'm proud of it," he says of the program, suggesting he's more surprised than are his musical onlookers.

Flutists can't help but be spoiled by the symphonic repertoire. Jeffrey Khaner, longtime Philadelphia Orchestra principal flutist, has intermittently made solo recordings and played recitals, but says "it would be very difficult to have a life as a musician without playing with the orchestra. The greatest music of all time - Beethoven, Brahms, Stravinsky - we would never be able to play if we weren't in an orchestra. The flute solo repertoire is lovely . . . but string instruments can be more attractive to composers. The depth of sound can be much greater."