The eight-page work, BWV 216, is known as the Wedding Cantata. It had been missing for 80 years when it turned up among the papers of Japanese pianist Chieko Hara after his death in 2001.

The cantata was written in 1728 for the wedding of a German customs official's daughter, and portrays an allegorical conversation between rivers representing the bridge and groom.

Rifkin, a conductor and composer, created instrumental parts for the cantata, which as it was found contains only soprano and alto parts, in German, for the seven-movement vocal work. Two of the movements had been recycled into other Bach compositions, with complete instrumentation.

Rifkin said his first impulse was to leave the work be. "Maybe a fragment should stay a fragment," he said. What he ended up with, he said, was not "[a reconstruction] of what Bach wrote, but I could give the people of today an idea of what his music was like. It sounds like Bach's music, but the listener should not know which part is Bach's and which part is mine."

Among his many areas of significant scholarship, Rifkin is best known for his argument, first presented in the early 1980s, that Bach used only one singer per part, rather than a chorale. He also helped spur a revival of interest in ragtime composer Scott Joplin when he made recordings of his works in the early 1970s.