The Mount Vernon Orchestra, based in southern Alexandria for the past three decades, recently changed its name to the Washington Metropolitan Philharmonic. Under this new and ambitious title, the group launched its 2004-05 season Sunday afternoon at the Church of the Epiphany in Northwest Washington.

Music director Ulysses S. James led the Philharmonic in a mostly unfamiliar and decidedly challenging program that was conducted with vigor and played with exuberance. The concert included plump, likable, academic Americana from the 19th century (Dudley Buck's "Festival Overture on the American National Air, The Star-Spangled Banner"), two works of faux-classical music by charismatic songwriters stretching their wings (Duke Ellington's "Black, Brown and Beige Suite" and George Gershwin's Piano Concerto in F) and a genuine oddity, the French composer Henri Tomasi's Trumpet Concerto.

Tomasi is remembered today, when he is remembered at all, as the conductor of a 1936 recording of Gluck's "Orfeo" with the extraordinary French mezzo-soprano Alice Raveau. (The late actress Irene Worth once told me she had never heard the essence of tragedy so achingly expressed by a singing voice.) Tomasi's Concerto dates from 1949 and provides a fierce workout for a virtuoso soloist, in this case the remarkable young trumpeter Alexander White, a local musician late of Fairfax County and currently in his first year at the Juilliard School. He played brilliantly, making the most of a vast dynamic range -- from blaring proclamation to muted, half-swallowed muttering -- and phrasing with unfailing lyricism and intelligence.

Although both of them have their moments, I think it safe to say that neither the Gershwin nor the Ellington piece would be in the repertory were it not for their creators' accomplishments in other genres. The pieces are too polite and excruciatingly self-conscious to be ranked as great jazz, and too disorganized and inchoate to be considered anything more than journeyman exercises in classical form. That said, the Gershwin concerto contains some juicy tunes (repeated over and over again, a la Edvard Grieg in his piano concerto, until you can't forget them, hard as you might try) and the Ellington is replete with delicious, quasi-minimalist vamps.

What impressed me about the performances was the stylistic ease with which James and his orchestra swung between classical and jazz -- that, and the rhapsodic yet meticulously detailed tenderness with which soloist Haskell Small played the Gershwin concerto. Hifalutin theorists to the contrary, jazz and classical music not only have very little to do with each other but (more to the point) don't really need each other very much. As such, it is a pleasure to find players so genuinely and generously polylingual.

Lest anybody fear that the Washington Metropolitan Philharmonic has forgotten its Mount Vernon roots, it should be noted that the concert will be repeated on Sunday night at Bishop Ireton High School, back in Alexandria. Information: 703-799-8229 or www.washingtonmetrophilharmonic.org.

The former Mount Vernon Orchestra launched its season with a new name and a challenging program Sunday at the Church of the Epiphany under the direction of Ulysses S. James.