The Urban Philharmonic, a new orchestra founded and conducted by Darrold Hunt, made its Kennedy Center debut yesterday afternoon. Organized to give special emphasis to black players in symphony orchestras, the 50-player ensemble yesterday had about two-thirds black players and one-third white.

In Beethoven's Coriolan Overture, the Mozart A Major Violin Concerto, and the Symphony No. 8 by Dvorak, the orchestra demonstrated a highly professional ensemble with strings that often turned silken, some polished, resounding horn playing, and a fine fist flute.

The program also was enhanced by two works by black composers: the familiar Night Music by Howard Swanson - who was in the audience to acknowledge the warm applause - and Lyric for Strings, a work of eloquent beauty by George Walker.

Sanford Allen was the stylish soloist in the Mozart Concerto, playing with a tone of admirable purity and quality. Hunt led his players throughout the afternoon with solid, musicianly taste, animated by a fine vitality and keen feeling for the lyric line.

The audience, while highly enthusiastic, was disappointing in size, numbering under 500. By the next concert, perhaps the word will have spread. It would be a welcome note if Hunt would explore the large repertoire that is deal for an orchestra of this size, as his colleague James DePreist is doing with the Quebec Symphony.