As delicate as the tone of the modern flute is, compared to its ancestor from the 18th century it might as well be a trumpet. Violinist Risa Browder, violist Steven Creswell and cellist John Moran, period-instrument players themselves, all know the challenge of keeping the exceptionally soft-voiced instrument in the musical conversation, and for Tuesday's Capitol Hill Chamber Music Festival concert at St. Mark's Church, they accompanied period flutist Jeffrey Cohan without sacrificing well-sprung rhythms or classical elan for lower volume.

Cohan began the evening by introducing "another little gem, hot off the Xerox machine down the street" at the Library of Congress: a pastiche flute quartet, crafted by Tebaldo Monzani from music by "Bach, Graf, Schroeter, Gambini and Others" (as the score at the library states). Despite his numerous sources, Monzani couldn't find enough melodies to fill the bland, overlong first movement, but the last two movements were briefer and more engaging.

A trio for flute, violin and viola by Franz Christoph Neubauer, a contemporary of Mozart, showed a keen sense of humor; the players made great sport of its cheekily abrupt slowdowns, purposefully awkward repeated notes and daringly quick modulations.

The group's reading of Beethoven's expansive early-period Serenade for the same instruments was marred by some uncertain intonation, but its stylish playing in a string trio by Luigi Boccherini made more of an impression than the music itself did. All four players gave Mozart's Flute Quartet in D, K. 285, a propulsive yet graceful performance to close the concert, with the flute leading the way in the merry chase of the finale.

-- Andrew Lindemann Malone