The fluid grace of the 18th-century concerto filled the Hall of Musical Instruments Friday night as the Smithsonian Chamber Players presented "Bach to Bach." The five pieces concentrated on harpsichord, with a string group carrying the tutti parts. Harpsichordists James Weaver and Kenneth Slowik played with balance, smoothness and, given the somewhat undynamic character of the harpsichord, considerable contrast. J. Reilly Lewis joined them on yet a third harpsichord for the third and closing pieces, giving the ensemble a fuller-bodied sound.

The string parts were uninspiring (not atypical of this genre) but correctly wrought, featuring violinists Melissa Graybeal and Lisa Rautenberg, violist David Cerutti, bassist Nicholas Pap and cellist Carla Rosenberg, the last having some difficulties staying in tune with the keyboard instruments. Especially delightful was the one piece on the program that was not by J.S. Bach, a more rococo concerto for two harpsichords by his son Wilhelm Friedemann Bach, with a decorative presto finale replete with glissandos and flourishes.

Some pleasant surprises were tucked away in the adagio sections of the concertos, a "Pizzicato" Adagio in BMV 1060, a languid "Alla Siciliana" in BMV 1063 and a chorale-style Adagio in BMV 1064, reminiscent of Bach's many church compositions. Precision was somewhat lacking overall, notably in the fugue movements, sacrificing the logical beauty Bach so depends on, but it improved in the final allegro, with its broader harmony and gentle ending.