Minstrel shows are the buffaloes of American show business. Born out of plantation entertainment and later co-opted by white performers working in blackface, they reached their peak between 1850 and 1870 before slowly disappearing. By 1919, only three minstrel companies remained although key elements survived in vaudeville. Now students and recent alumni of the Duke Ellington School of the Arts have injected new life into minstrelsy.

"Puttin' On the Mask," a minstrel show playing for free at the Kennedy Center's Terrace Theater tonight through Saturday, packs more entertainment than it seems fair to give away. Mike Malone, the creator, choreographer and director of the show, has drawn on the Library of Congress and the music of James A. Bland and W. C. Handy to put together a driving, exciting musical pastiche.

In part one, he sends out the traditional cast: A master of ceremonies swaps atrocious jokes with a tambourine player and a "bones" player, and a supporting company frames the comics in a semicircle, supplying the 19th-century equivalent of a laugh track.

In part two - called the "Olio" because the original minstrels performed it in front of a second curtain of that name - members of the company display their special talents in singing, dancing and mimicry. The third part present a little musical within a musical.

The Ellington minstrels undoubtedly would have had the duke himself clapping madly. James Exum and Chuck Lewis dance like fledling dervishes, and master of ceremonies Kenneth Daugherty glides through his playful affectations without a false move. What the rest of the cast lacks in professional polish - and it's not much - they easily make up for in sheer power.

"Puttin' On the Mask" may become a habit for some of the Ellingtonians. This show could go places.