Aside from its elaborate special effects, a story that parallels Shakespeare’s The Tempest, a Freudian subtext, and a pre-ham Leslie Nielsen, the most memorable thing about the 1956 sci-fi film Forbidden Planet is the Karlheinz Stockhausen-influenced electronic score by occasional John Cage collaborators Louis and Bebe Barron. “Electronic Tonalities” deftly color the on-screen action with a superb array of sounds from the bleeps-and-bloops school of electronic composition. At 9:30 p.m. tonight and at 8:45 p.m. tomorrow at the Kennedy Center’s American Film Institute Theater. $6. (202) 785-4600. (Christopher Porter)