CHICAGO  On a frigid Wednesday night in December 1959, a revolution in comedy began here, almost unobserved. In a partly refurbished Chinese laundry in a bohemian neighborhood, a small improvisational troupe calling itself the Second City took to the stage for the first time to satirize the foibles of the Eisenhower era for an audience of barely 100, with a few bentwood chairs the only props.  Back row, John Candy, left, and Dan Aykroyd; front, from left, Rosemary Radcliffe, Eugene Levy and Gilda Radner in 1974.  The latest on the arts, coverage of live events, critical reviews, multimedia extravaganzas and much more. Join the discussion.  From left, Tina Fey, Scott Allman and Rachel Dratch in 1996.  Sally Ryan for The New York Times  Second City alumnus Tim Meadows, at an anniversary performance in Chicago.  Sally Ryan for The New York Times  Rachel Dratch and Scott Adsit.  Sally Ryan for The New York Times  Since that initial Dec. 16, millions have attended Second City shows or watched the troupe’s scores of alumni on television or in films. Second City is often likened variously to a comedy factory, farm team, finishing school or “Harvard of humor,” and its graduates include Alan Arkin and Joan Rivers from the early years, Bill Murray, Chris Farley and Mike Myers from later eras and Tina Fey and Stephen Colbert more recently.  Now ensconced in larger quarters just down the street in Old Town, but with the same style of chairs still onstage, Second City commemorated its 50th anniversary over the weekend with shows, parties and panel discussions that, more than one performer said, “felt like a high school reunion.” Highlights will be broadcast as a TBS special next June and will soon be posted at the troupe’s Web site, secondcity.com. But with the entertainment industry struggling to adapt to shifting tastes and new modes of expression, the gathering also served another purpose: to underline how the conception and execution of what is considered funny has changed, thanks to Second City.  At the time of the company’s birth, the dominant style in American comedy was stand-up, often with a strong dollop of borscht-belt shtick. From the start, Second City stood in contrast to that approach: it emphasized an ensemble, not the individual performer; improvisation rather than a written routine; sketches instead of jokes; and intellectual rather than slapstick humor.  “We came from the theater, and that affects the way you act, construct your scenes and think about your audience,” Bernard Sahlins, the only surviving founder of Second City, said in an interview on Friday. In those early years, he added, when he auditioned performers, “I would sometimes ask, ‘Have you read Dostoyevsky? Who is the secretary of agriculture?,’ because I wanted us always to be playing at the top of our intelligence.”  Today few Second City sketches run as long as the 10 to 12 minutes that were not uncommon a half-century ago (audiences weaned on television are less patient), and there are more likely to be curse words and references to television than to 19th-century Russian literature. But the environment in which the troupe operates has changed even more drastically, which affects the expectations of the performers.  In those early years “comedy was not the economic commodity that it is now, and you weren’t practicing it for that reason,” said David Steinberg, who was part of a mid-1960s cast that also included Robert Klein and Fred Willard, went on to a successful stand-up career and today directs television shows. “It was a different kind of commitment then. We were all misfits, outsiders, University of Chicago dropouts, connecting as a group, a community. There was no plan, no other goal, no thought of getting a show or a series or doing anything other than this.”  Nowadays a stint with Second City is often just a stage in a larger career strategy whose trajectory has been established by the example of all those successful alumni. A Second City credential can confer so much credibility that “some people lie about it” at auditions, said Tami Sagher, an alumna who has written for “30 Rock” on NBC and “Psych” on USA and appeared in “Curb Your Enthusiasm” on HBO and the film “Knocked Up.” What transformed Second City into an institution with national reach was “Saturday Night Live.” The original cast included three Second City alumni  John Belushi, Dan Aykroyd and Gilda Radner  and ever since then, the company has been such a permanent pipeline for that NBC show, supplying about two dozen performers and even more writers, that staff members here recall Mr. Sahlins growing glum or irritated every time Lorne Michaels, executive producer of “Saturday Night Live,” came to see a revue.  But in retrospect, several of those who trod the path to “SNL,” as the show is often called, seemed to prefer the work they did at Second City. At a panel discussion Rachel Dratch, who left the show in 2006, said that she “felt freer here” in Chicago; Tim Kazurinsky, an early-’80s cast member, said “SNL” seemed “a little bit toothless” by comparison; and Horatio Sanz (on the air from 1998 to 2007) lamented that “at ‘SNL’ you have to have the joke on the first page” of a script, whereas Second City allowed the performer-writer to “do what you wanted to do, to put in a 30-year-old reference and say, ‘Deal with it.’ ”  Second City’s 50th anniversary occurs at a moment when the company’s influence and prestige may be at a peak, even as television itself seems desperate to find new forms and approaches. Alumni of the troupe represent three of the most highly praised shows on the air right now: Steve Carell in “The Office,” Mr. Colbert on “The Colbert Report” and Ms. Fey on “30 Rock.”  Ms. Fey was not part of the weekend’s events, though several other “30 Rock” actors and writers who also trained at Second City were, including Scott Adsit and Jack McBrayer. But an alumni reunion show on Saturday night included Mr. Colbert and Mr. Carell, who revived a surreal sketch in which they return to Mr. Colbert’s Southern hometown only to find themselves transformed into elderly black women named Shirley and Sarah.  The television show that probably most reflects a Second City sensibility, however, is “Curb Your Enthusiasm,” the Larry David series that has been nominated for 30 Emmys since 2000. Jeff Garlin and Shelley Berman, who play Mr. David’s manager and father, are products of the Second City system, just like Mr. Steinberg, who has directed several episodes, and various guest stars.  “ ‘Curb Your Enthusiasm’ could not exist without Second City,” Mr. Garlin said at a panel discussion on Sunday. That comedy series works from an outline, not a detailed script, to encourage improvisation. “It was always planned that way from the beginning, and that’s Second City,” he added.  Over the years Second City has also become a commercial brand  a notion that would probably have been fodder for the beatnik and hippie types who flocked to the troupe in its early years. It has national and international touring casts, has opened branches in places like Las Vegas and Detroit, has signed a deal a few years ago to provide comic troupes on Norwegian Cruise Line vessels, and organizes workshops for businesses on team building and communication skills.  In addition, thousands of people have enrolled in its courses that teach improvisation, and there is even a program in which college students receive credit for comedy studies. At one such class last week, undergraduates analyzed sketches on YouTube that ranged from Ernie Kovacs to the sitcom “It’s Always Sunny in Philadelphia.”  Second City’s newest venture is a unit that will specialize in short-form video, with offices in Chicago and Los Angeles and an eye to developing material that can be made into series. In the 1970s and ’80s the Emmy-winning television show “SCTV,” with Martin Short, Catherine O’Hara, Harold Ramis, Eugene Levy and others largely from the Toronto branch, was an underground hit of sorts, and “finding the brass ring a second time is where my head is at,” said Andrew Alexander, Second City’s chief executive.  “For me, the growth now is in trying to get more on TV, which is a great way of promoting yourself,” he added. “We’ve gone the traditional road in developing TV shows and done pilots for everybody, but the stars never aligned, and now we are trying it a different way.”  Onstage here, however, the original Second City ethos and approach continue strong. The current revue, the troupe’s 97th, is called “Taming of the Flu” and pokes fun at political figures like Mayor Richard M. Daley of Chicago and the French president, Nicolas Sarkozy; includes a pointed skit on race and class; and has a third act that is totally improvised.  “What drew me here in the first place was a renegade, anti-establishment attitude that I connected with,” said Brad Morris, a member of that cast. “This is still a place where you can do whatever the hell you want, and if you do it right, when you leave here, you can write, act and even direct. Nobody here is ever a one-trick pony.”
The celebration of the improvisational troupe’s 50th anniversary was a reminder of how it changed the tone of comedy.