Many late night talk shows feature a house band which generally performs cover songs for the studio audience during commercial breaks and occasionally will back up a guest artist.
Late-night talk shows are a popular format in the United States, but are not as prominent in other parts of the world.
A nationwide prohibition on tobacco advertising that took effect in 1971 prompted NBC to extend its broadcast day by an additional hour with programming it hoped would recuperate some of that lost revenue.
NBC's two other rivals during the early television era, CBS and ABC, did not attempt any major forays into late-night television until the 1960s.
ABC's first effort at late-night TV was hosted by Les Crane, which pioneered the controversial tabloid talk show format that would not become popular until two decades later. Shorter still was The Las Vegas Show, a Las Vegas-based late-night show hosted by Bill Dana that was the only offering of the United Network that ever made it to air (because that network only had a handful of affiliates, it also syndicated to CBS, ABC and independent stations); it, along with the network, only lasted five weeks in summer 1967.
Shows that loosely resemble the format air in other countries, but generally air weekly as opposed to the nightly airings of those in the United States.
They also generally air in time slots considered to be prime time in the United States.
The late-night talk show format was popularized, though not invented, by Johnny Carson with The Tonight Show Starring Johnny Carson on NBC.
Typically the show's host conducts interviews from behind a desk, while the guest is seated on a couch.
CBS went without late-night TV until 1969, when it acquired The Merv Griffin Show from syndication; Griffin returned to syndication in 1972, and CBS would not air any further late-night talk shows until 1989, instead opting for reruns, lifestyle programs and imported Canadian dramas in the time slot.
By the 1960s, NBC had already cornered the market for late-night television viewing and would go on to dominate the ratings for several decades.
Paar permanently left the show in 1962, citing the reason that he could not handle the work load of The Tonight Show (at the time, the show ran 105 minutes a day, five days a week), and he moved to his own weekly prime-time show, which would run until 1965.