Change in tone
As the series progressed, it made a significant shift from being primarily a comedy to becoming far more drama-focused. Changes behind the scenes were the cause, rather than the oft-cited cast defections of McLean Stevenson, Larry Linville, Wayne Rogers and Gary Burghoff. Executive Producer Gene Reynolds left at the end of the fifth season in 1977. This, coupled with head writer Larry Gelbart's departure the previous season, stripped the show of its comedic foundation. Likewise, with the departure of Larry Linville after five seasons, the series lost its "straight man" (comic foil).
Beginning with the sixth season, Alan Alda and new Executive Producer Burt Metcalfe became the "voice" of M*A*S*H, and continued in those roles for the remaining five seasons (though Alda and Gene Reynolds became Executive Consultants). By the eighth season in 1979, the writing staff had been totally overhauled, and M*A*S*H displayed a different feel—consciously moving between comedy and drama, unlike the seamless integration of years gone by. While this latter era showcased some fine dramatic moments, the attempts at pure comedy were not as successful as compared to the first five seasons. The quirky, fractured camp of the early years had gradually turned into a homogenized "family"; clever dialogue gave way to puns; and the sharply defined characters were often unrecognizable and lost most of their comedic bite.[original research?] In addition, the episodes became more political, and the show was often accused of preaching to its viewers. At the same time, many episodes from the later era were praised for its experimentation with the half-hour sitcom format, including "Point of View" (an episode shown from the POV of a wounded soldier), "Dreams" (which show the lyrical and eventually disturbing dreams of the 4077 personnel), "A War For All Seasons" (which takes place over the course of 1951), and "Life Time" (which takes place in real time).
Another change was the infusion of story lines based on actual events and medical developments that materialized during the Korean War. Considerable research was done by the producers, including interviews with actual MASH surgeons and personnel to develop story lines rooted in the war itself. Such early 1950s events as the McCarthy era, various sporting events, and the stardom of Marilyn Monroe were all incorporated into various episodes, a trend that continued until the end of the series.
While the series remained popular through these changes, it eventually began to run out of creative steam. The producers would get phone calls from actual Korean War doctors, telling them experiences they had and wanted to include those into upcoming episodes. According to Burt Metcalfe, they had to refuse some (if not all) storylines from the doctors, saying they had used them up in previous episodes. Harry Morgan, who played Col. Potter, admitted in an interview that he felt "the cracks were starting to show" by Season 9, and the cast had agreed to make Season 10 their last. CBS decided otherwise, saying that their hit show wasn't going to go away so suddenly. Ultimately, CBS persuaded the cast and crew to produce half a regular season of episodes for the final year (making an official run of eleven seasons) and end the series with a big finale, which ultimately became one of the most watched episodes in television history.