"Imagination Celebration -- 1979," the Kennedy Center's third annual Children's Arts Festival, will feature two new works when it opens for a two-week run after a preview April 1.

Kennedy Center Chairman Roger L. Stevens said yesterday the festival will include more than 50 free performances of seven different productions in the Terrace Theater, as well as workshops and conferences. It will run through April 14.

Performances will include the Empire State Youth Theatre's Kabuki version of "Sleeping Beauty," Alliance Theatre Umbrella Player's "The World of Folk Tales," New York City Opera Theater's "The Toy Shop" and United Stage's "Feast of Folk Tales." A potpourri of mime also will be presented April 8 in cooperation with National Mime Week.

Jean Kennedy Smith, chairman of the Kennedy Center's Education Committee, said a sampling of the two works commissioned for the festival, and appearances by heavyweight champion Muhammad Ali and New York City Ballet's Jacques d'Amboise will highlight the invitational opening in the Terrace Theater.

"Encounter With Dance," choreographed by d'Amboise, will feature young, deaf dancers from the National Institute of New York City and the "Deaf Shall Dance" project of the University of Utah.The work will be presented as a joint project of the Kennedy Center, Smith said, and the National Committee, Arts for the Handicapped.

Also developed for the festival, "Joy, a Musecal Tribute to Duke Ellington," was produced by composer Stan Keen and will be performed by the Northwest Jazz Sextet.

As part of the Kennedy Center's educational outreach program, these new works and other productions from the festival will be presented for one week in Chicago and Seattle after the Washington engagement. Free tickets for all local public performances will be distributed in the Kennedy Center Hall of States March 31 and April 1 between 10 a.m. and 2 p.m.