Cosby pursued a variety of additional television projects and appeared as a regular guest host on "The Tonight Show" and as the star of an annual special for NBC. In 1969, he returned with another series, "The Bill Cosby Show", a situation comedy that ran for two seasons. Cosby played a physical education teacher at a Los Angeles high school. While only a modest critical success, the show was a ratings hit, finishing eleventh in its first season. Cosby was lauded for using African-American performers such as Lillian Randolph, Moms Mabley, and Rex Ingram as characters. According to commentary on the Season1 DVDs for the show, Cosby was at odds with NBC over his refusal to include a laugh track in the show, as he felt viewers had the ability to find humor for themselves when watching a TV show.