The Firesign Theatre are a comedy troupe consisting of Phil Austin, Peter Bergman, David Ossman, and Philip Proctor. Founded by Bergman, the troupe began as live radio performers in Los Angeles, California on radio stations KPPC and KPFK during the late 1960s and early 1970s.
The name is an astrological reference: The members consist of an Aries (Austin), a Leo (Proctor), and two Sagittarians (Bergman and Ossman). It is unclear whether the name also is intended as a pun on "Fireside Theatre," a name that has been applied to several things, including a popular early TV show that the members certainly would remember, though their roots are in radio.
Called "The Beatles of Comedy" by their admirers, the Firesign Theatre specialize in audio recordings, having had relatively little presence in stage performance, television or movies. Over the course of their career, they have sold more audio recordings in total than any other comedy act. Their first four albums in particular are considered classics of recorded comedy. (Each of those four albums features a different one of the four members in a leading role.)
While their free-flowing, stream of consciousness style has the feel of improvisational comedy and may derive from improvisational processes, most of it actually is tightly scripted and memorized. They have employed a writing method that demands the consent of all four members before a line can be included. Much of their work has been copyrighted under the name "4 or 5 Crazee Guys," reflecting their collective sentiment that there is a "fifth guy in the room" who actually is doing all the writing.
Because of their complexity, Firesign recordings tend to become funnier with repeated listenings as new jokes are revealed, and their high production values provide an additional layer of aesthetic pleasure that endears them to audiophiles.
Similarly, Firesign Theatre productions take place in a satirical world with many subtle and oblique references to mass culture which fans enjoy decoding. A Firesign Theatre lexicon for the perplexed (http://www.faqs.org/faqs/firesign-theatre/lexicon/part1/).
During the mid-1970s, the group more or less split in half: Firesign productions continued, but Proctor and Bergman also performed as a duo, and the other two likewise worked together and also individually. In the mid-1980s, Ossman temporarily left to produce shows for National Public Radio.
Their recordings through 1975 were originally released by Columbia Records and may be currently available from Rhino Records.
(* as "Firesign Theatre", but without David Ossman)