There's very little to be seen and heard in the 10 installments of American Cinema that is new, but that's exactly why it's so much fun to watch. In this case, familiarity breeds contentment. A history of the movies that breaks its subject up into bite-size genre pieces (episode titles include ''Romantic Comedy,'' ''The Western,'' and ''Film Noir''), American Cinema combines vintage clips and fresh interviews with actors, directors, writers, and scholars, including Clint Eastwood, Martin Scorsese, Steven Spielberg, and Quentin Tarantino. This documentary series is entertaining despite being so utterly conventional. And the timing for American Cinema could not be better: If ever there were an engrossing yet utterly inoffensive bit of PBS programming to reassure Newt Gingrich that public broadcasting is indeed a right-thinking, patriotic business, this is it.
Don't be put off by American Cinema's relatively slow start. Its opening hour, ''The Hollywood Style,'' is one of those sweeping-generalization overviews of both subject and series that lead to superfluous voice-over narration like this: ''Audiences quickly developed preferences in the kinds of movies they wanted to see.'' Duh.
But most of the time, American Cinema, hosted by John Lithgow, is well written and discriminating in its selection of movie scenes and commentators. For every seen-it-a-thousand-times clip from Casablanca, there's a quick, incisive look at a lesser-known movie that distinguishes its genre, such as Gun Crazy, the deliriously urgent 1949 film noir whose director, Joseph Lewis, is articulate and funny in describing the bleak mood he tried to achieve. Indeed, ''Film Noir,'' the eighth episode in American Cinema, is one of the best installments, mixing classic B movies and shrewd commentary by, among others, director Kathryn Bigelow, herself a contemporary film-noir adept (Near Dark and Blue Steel). Bigelow's analysis of the roles women played in thrillers of the '40s and '50s is feminist film criticism at its most lucid.
American Cinema nonetheless gradually reveals a crucial weakness: the lack of a provocative theory of the movies that would give the series a structure and purpose and distinguish it from the many histories of motion pictures that have come before. If it had presented a stronger point of view or advanced an argument, it could have done for the movies what Robert Hughes' unforgettable 1981 PBS series The Shock of the New did for modern art.
Instead, over the course of its 10 hours, American Cinema struggles to express the sentiment that Pauline Kael tossed off more than 30 years ago in a review of Hud: ''What gave the Hollywood movie its vitality and its distinctive flavor was that despite the melodramatic situations, the absurd triumphs of virtue and the inordinate punishments for trivial vice perhaps even because of the stale conventions and the necessity to infuse some life that would make the picture seem new within them the 'feel' of the time and place came through, and often the attitudes, the problems, the tensions.'' Such insights fail to surface in American Cinema, but that doesn't mean you won't have a fine time watching chunks of great movies and listening to smart remarks by many of the people who made the films. B+