This year’s installment of the Capitol Hill Chamber Music Festival opened with another observation of the tricentennial year of the birth of C.P.E. Bach. On Saturday night at St. Mark’s Episcopal Church, flutist Jeffrey Cohan, violinist Marlisa del Cid Woods and harpsichordist Joseph Gascho offered a sampling of music by J.S. Bach’s most famous son.

Cohan performed on an 18th-century transverse flute, and the chance to hear this music on an instrument from Bach’s time in this intimate acoustic was worthwhile. In two trios for this combination of instruments, Wq. 143 in B minor and Wq. 149 in C, del Cid Woods and Gascho are to be commended for never overpowering the flute’s pale, often fragile tone. These pieces are among the best in the composer’s chamber music output, contrapuntally intricate and with daring chromatic touches.

In a solo outing, Gascho shifted skillfully between manuals to achieve the contrast of piano and forte in Bach’s Sonata in C minor, Wq. 48/4 (the fourth “Prussian” sonata), adding some pleasing embellishments and using a cadenza found in one source for the second movement. Del Cid Woods produced a laser-focused, pretty tone on her violin, so it was a shame that she had no piece to showcase her.

Instead, most of the programming was focused on Cohan, whose tone became timorous at times in the unaccompanied Flute Sonata in A minor, Wq. 132, wilting at the top of its range. Worse, Cohan took extreme rhythmic liberties even in the ensemble pieces, perhaps trying to create an unpredictable quality by adding so many coy hesitations that there were scarcely two bars taken in strict meter. All music needs some freedom, but Cohan’s willful approach undermined the intricate overlapping of lines, like a complex watchwork gummed up with dust.

Downey is a freelance writer.

Violinist Marlisa del Cid Woods. (Jennifer Jackson Lewis)