Harpischordist James Weaver and cellist Kenneth Slowik rendered the geometric musings of J.S. Bach Sunday evening at the Carmichael Auditorium of the National Museum of American History. It was the first of three programs by the Smithsonian Chamber Music Society that will encompass Bach's six English Suites for harpsichord and six Suites for Violoncello Solo.

Before seating himself at the Dulcken harpsichord made in 1745, Weaver explained that the first concert he heard at the Smithsonian in 1965 was played on the same instrument. Weaver offered a trenchant reading of the Suite in E Minor, BWV 810, with its Italianate elements in the Prelude and mathematical flourishes repeating similar passages with different tempos. Weaver never faltered in hewing the melodic line to the dance purpose of the Allemande, Courante, Sarabande and Gavotte in both Suites. But there was a false start in the Sarabande of the Suite in A Minor, BWV 807. After a moment of frowning consternation, Weaver recovered his place in the music and tinkled briskly through the Bourrees.

We may think this is the way Bach intended his music to sound, but with no manuscript surviving for the six cello solos written with Bach's notations, interpretation defaults to the musician. Fortunately, Slowik displayed consummate familiarity with the material, playing from memory Bach's Suite in G, BWV 1007, and the Suite in C Minor, BWV 1011, on two plangent-toned violoncellos made by Antonio Stradivari in 1688 and 1701.