These shows were sealed off from each other, too, and from the rest of pop culture. Beyond that TV staple, the wildly implausible guest star appearance, like when Dizzy Gillespie plays Vanessa's music teacher, '80s sitcoms were loathe to acknowledge other mass media, too. The characters never went to movies or rock concerts like the rest of us. They never wore t-shirts emblazoned with advertising for shoe companies and soft drinks. With the notable exception of Roseanne, they also never showed characters doing something that most Americans, then and now, enjoy for several hours a day: watching television.

In 1989, The Simpsons exploded into pop consciousness and changed everything. Marge and Homer, working class Baby Boomer parents with three Generation X kids, were the first family on TV to address the problems of living in a mass society. The Simpsons were first to capture how it feels to live in an America utterly saturated by mass media, where kids are casually obsessed with hyper-violent cartoons, and someone you will never meet, like a local anchorman, plays an intimate role in your daily life. The Simpsons, in essence, were the first characters on TV to be as dramatically affected by pop culture as the rest of us.

By the mid-1990s, the first wave of Generation X was hitting 30. Bart and Lisa's cohort, the first generation to never know a world without TV, was old enough to start writing TV shows of their own. References to pop culture started pouring into the once hermetically sealed sitcom world. On Buffy the Vampire Slayer, characters would casually mention movie stars and rock bands. Jerry Seinfeld got in trouble for making out with his girlfriend during Schindler's List. Eric on That '70s Show imagined himself as Luke Skywalker.

By the 2000s, shows were doing more than just incorporating pop culture. They were making fun if it. South Park and Arrested Development, the only real rivals to Community's meta-comedy crown, mocked the conventions of film and TV. A whole wave of "backstage" shows, including The Flight of the Conchords, Entourage, and Curb Your Enthusiasm, satirized the entertainment industry from the inside. Maybe the best of them, premiering in 2006, is 30 Rock.

Tina Fey is a brilliant innovator—Lisa Simpson all grown up—and there is no question 30 Rock built the road Community drives on. Still, for all of 30 Rock's meta-humor and nods to the audience, it's a fairly conventional workplace comedy at heart. Essentially it's a reworked version of Mary Tyler Moore, with Tina Fey in Mary's role, Alec Baldwin as the Lou Grant-like figure, and Tracy Morgan reprising Ted Baxter.

Community is Something Completely Different, and its relationship to 30 Rock is more than a little like that of The Colbert Report to The Daily Show.

Where Jon Stewart's show makes fun of pundits, The Colbert Report is, in itself, a spoof of punditry. In the same way, Dan Harmon, Bart Simpson all grown up, isn't making a sitcom. He's making a parody of them.