Falsettos. By William Finn. Sanders Theatre, 8 p.m. Tickets are available at the Sanders Theatre Box Office at 496-2222 or at the door. $7.

Six Degrees of Separation. By John Guare. Loeb Experimental Theatre, 7:30 p.m. Free.

17 March Friday

Conference

The Past, Present and Future of Nuclear Weapons. A presentation in honor of Donald Horning, professor of chemistry emeritus, Harvard School of Public Health. Call 432-3314 for registration and details.

The First Congress on the Psychology of Investing. Through Saturday, March 18. The unique two-day Congress will bring together a faculty of seminal educators and leaders in the fields of investment and psychology. $295. Call 734-1300, ext. 469 for more information.

Dance

Annual Performance of Modern Dance. By the Harvard-Radcliffe Dance Company. Radcliffe Dance Center, 8 p.m. Friday and Saturday. $5.

Film

Harvard Film Archive. Carpenter Center for the Visual Arts. 24 Quincy St. 495-4700. $5 for students, unless a special event. "The Tourist and Burckhardt 1" at 7 p.m., with Burckhardt in person. "Arizona Dream" at 8:45 p.m.

Movie

Strange Brew. Presented by the Harvard-Radcliffe Canadian Club. Science Center, 8 and 10 p.m. $3.

Opera

La Boheme. Lowell House Dining Hall, 8:30 p.m. $6 for students.

Theatre