NEWTON-The David Leonhardt Jazz Group, relying on improvisation to perform original compositions, and jazz and American standards, will present "An Evening of Gershwin" and "Jazz for Kids," 7 p.m., Friday, Feb. 4, at Sussex County Community College, where its residency activities include workshops, lectures, and an introductory jazz performance for children. The Village Voice called The David Leonhardt Jazz Group "first-rate jazz." Leonhardt, a composer and pianist, has 30 years of professional experience including recordings, television, and concerts. His group has been heard at The Apollo Theater, The Blue Note, Birdland, and festivals worldwide. The Los Angeles Times said, "David Leonhardt is an intense and swingin' artist, alert to every mood." Admission $3 and free to students. For information, call 300-2116.