Stand up comedy is perhaps the easist field of entertainment for new talent to enter, in the sense that many smaller venues hold "open mic" events where anyone who dares to can have a shot at performing comedy before a live audience. However, more than any other performer, the stand up comedian is at the mercy of the audience, which is an integral element of the stand up comedian's act. A truly adept stand up comic must nimbly play off the mood and tastes of any particular audience, and adjust his or her routine accordingly. The test of a master stand up comedian is the ability to not only face down a "heckler", but to be able to retort to in a way that wins over and entertains the rest of the crowd.
American stand up comedy has it's roots in various traditions of entertainment popular in the late 19th century, ranging from vaudeville and humorist monologues (with Mark Twain a notable master), to Yiddish theatre and circus clown routines. Most early comedians were merely viewed as "joke tellers", who warmed up the audience as an opening act, or kept the crowds entertained during intersessions. Being a comedian was often considered a stepping stone to a proper career in show business. Jokes were generally broad and (off when not broadcast) mildly risquée, and often dwelt on stock comic themes ("mother-in-law jokes", ethnic humor). "Blue humor", or comedy that was considered indecent, was popular in many nightclubs, but working "blue" greatly limited a comedian's chance for legitimate success.
Beginning in the late 1950s and into the 1960s, a new generation of American comedians began to explore political topics, race relations, and sexual humor. Stand up comedy shifted from quick jokes and one liners to monologues, often with dark humor and cutting satire. Lenny Bruce became particularly influential in pushing the boundaries of what was considered acceptable entertainment at this time. African American comedians such as Redd Foxx, long relegated to segregated venues, also began to cross over to white audiences at this time.
Stand up comedy exploded during the 1970s, with several entertainers becoming major stars based on stand up comedy performances. Stand up expanded from nightclubs and theaters to major concerts in sports arenas. Richard Pryor and George Carlin followed Lenny Bruce's acerbic style to become counterculture icons. Steve Martin and Bill Cosby had similar levels of success with gentler comic routines. The older style of stand up comedy was kept alive by Rodney Dangerfield and Buddy Hackett, who enjoyed revived careers. Television programs such as Saturday Night Live and The Tonight Show launched the carrers of other stand up comedy stars.
The great popularity of stand up comedy led to a boom in stand up comedy venues for both locally based and touring comics in many cities. Many stand up stars landed major television deals, and established television and film stars such as Robin Williams, Eddie Murphy, and Billy Crystal tested their comic chops with live stand up comedy appearances. The advent of HBO (which could present comedians uncensored) and other cable channels such as Comedy Central further fulled the stand up comedy boom.
By the 1990s, the glut of stand up comedy led to a decline in stand up comedy, as the market became somwhat flooded with mediocre comics. However established stand up comics still command top ticket prices, and talented new comedians still have many small venues to establish themselves in.