The 300-year-old Bach had a sparkling presentation of his "Coffee Cantata" last night at the Museum of American History, and it was as fresh as the day it was brewed.

The codirector of the Smithsonian Chamber Players, Kenneth Slowik, invited the audience to "please feel free and enjoy yourself." The greatest enjoyment came from the three singers, soprano Ann Monoyios, tenor Manuel Melendez and bass Richard Dirksen. They made singing the florid and difficult Bach lines sound easy, giving the notes a lilt that is rare with the Bach singer; and their German diction was perfect.

Every nuance came through, and it came through musically as well. They had superb support from the Smithsonian Players, particularly from Christopher Krueger, who gave the baroque flute vocal dimensions. He took his cue from Moyonios, who has a soprano voice that is pure and agile. Nothing seemed difficult for her, and that makes listening a joy. The cantata was so clean and bright that one hoped the ensemble would do the whole piece one more time just for the pleasure of the moment.

The two other Bach works on the program were instrumental, the C Minor Sonata for violin and harpsichord and the C Major Suite for solo cello. Both performances had considerable grace, though one would have preferred the violin of Nancy Wilson to have assumed a greater share of the partnership with harpsichordist James Weaver. The cello suite was given a very personal interpretation. Cellist Slowik took care to project the polyphonic intentions inherent in the music, defining the phrases with careful articulation.

Early in the Bach tricentennial year, the concert set what one hopes is the standard of all the Bach concerts yet to come.