A single genre links Russian folk music to Depression-era cartoon soundtracks, early jazz and the compositions of Gershwin and Prokofiev -- klezmer. Though klezmorim have always grappled with a reputation as ragtag party pipers, the art form has made an indelible impression on musicians as diverse as Mendelssohn and Benny Goodman.

As entertainers for an uprooted people, klezmorim are extremely deft at adapting to just about all instruments and idioms that come their way. The Machaya Klezmer Band, which played a packed Social Hall last night at the Jewish Community Center of Greater Washington, adheres faithfully to the klezmer played by the first stream of Russian Jewish immigrants to the United States, who layered elements from the Yiddish theater onto languorous, longing ballads like "Boots." Appropriately, Machaya eschews the pop fusions that characterize "new wave" klezmer.

But neither musical content nor instruments make klezmer klezmer. The word's meaning depends on the performers, who must lavish their pieces with considerable ornamentation and expressive dissonance. In the freilachs (dances that start out slow and pick up speed), clarinetist Fred Jacobowitz had a way of smacking and bending the notes until they literally screamed. He also sparkled in two selections by 1930s band leader Sid Becket. Each octave slide, quick run or startling key change somehow seemed to be tailor-made for Jacobowitz.

Machaya shaped the evening as a time to play a few freilachs, tell a few Jewish jokes and get everyone dancing in a big circle. For the last two projects, in addition to her bel canto delivery of the evening's Yiddish songs, Frieda Enoch deserves credit.