Guest star Sid Caesar portrays his classic "professor" in appearance set for Sesame Street's 15th anniversary season, which begins on the nation's 302 PBS station on Nov. 19, 1985. Oscar the Crouch teaches the professor between "loud" and "quiet" in a segment that will be broadcast.

AP

Guest star Sid Caesar portrays his classic "professor" in appearance set for Sesame Street's 15th anniversary season, which begins on the nation's 302 PBS station on Nov. 19, 1985. Oscar the Crouch teaches the professor between "loud" and "quiet" in a segment that will be broadcast.