The origins of The Doors lay in a chance meeting between acquaintances and fellow UCLA film school alumni Jim Morrison and Ray Manzarek on Venice Beach California in July 1965. Morrison told Manzarek he had been writing songs (Morrison said "I was taking notes at a fantastic rock-n-roll concert going on in my head") and, with Manzarek's encouragement, sang "Moonlight Drive". Impressed by Morrison's lyrics, Manzarek suggested they form a band.

Keyboardist Manzarek was in a band called Rick & the Ravens with his brothers Rick & Jim Manczarek, while drummer John Densmore was playing with The Psychedelic Rangers, and knew Manzarek from meditation classes. In August, Densmore joined the group and, along with members of The Ravens and bass player Pat Sullivan (later credited using her married name Patricia Hansen in the 1997 box CD release), recorded a six-song demo in September 1965. This circulated widely as a bootleg recording and appeared in full on the 1997 Doors box set.

That month the group recruited guitarist Robby Krieger, and the final lineup — Morrison, Manzarek, Krieger and Densmore — was complete. The band took their name from the title of a book by Aldous Huxley, The Doors of Perception (1954). That title was in turn taken from a line in a poem by the 18th-century artist and poet William Blake: "If the doors of perception were cleansed, every thing would appear to man as it is: infinite".

The Doors were unusual among rock groups because they did not use a bass guitar when playing live. Instead, Manzarek played the bass lines with his left hand on the newly invented Fender Rhodes Piano Bass, an offshoot of the Fender Rhodes electric piano, playing other keyboards with his right hand. On their studio albums (with the notable exception of their eponymous first record), The Doors did, however, use bass players, such as Jerry Scheff, Doug Lubahn (who also played with Clear Light), Harvey Brooks, Kerry Magness, Lonnie Mack, Larry Knechtel, Leroy Vinnegar, and Ray Neapolitan.

Many of The Doors' original songs were group compositions, with Morrison or Krieger contributing the lyrics and an initial melody, and the others providing harmonic and rhythmic suggestions, or even entire sections of songs, such as Manzarek's organ introduction to "Light My Fire".

By 1966, the group was playing the London Fog club and soon graduated to the prestigious Whisky a Go Go, where they were the house band, supporting acts including Van Morrison's group Them. On their last night together the two bands joined up for "In the Midnight Hour" and a twenty-minute jam session of Them's "Gloria". On August 10, they were spotted by Elektra Records president Jac Holzman who was present at the recommendation of Love singer Arthur Lee, whose group was on Elektra. After Holzman and producer Paul A. Rothchild saw two sets of the band playing at the Whisky a Go Go, they signed them to the Elektra Records label on August 18—the start of a long and successful partnership with Rothchild and engineer Bruce Botnick.

The timing was fortunate, because on August 21 the club fired the band after a profanity-filled performance of "The End". In an incident that foreshadowed the controversy that later followed the group, an acid-tripping Morrison raucously recited his own version of the Greek drama Oedipus Rex, in which Oedipus kills his father and has sex with his mother.

'The Doors' self-titled debut LP was released in the first week of January 1967. It featured most of the major songs from their set, including the 11.5-minute musical drama "The End". The band recorded their first album at Sunset Sound Recording Studios - 6650 West Sunset Boulevard, Los Angeles, CA, Wed. Aug. 24 - Wed. 31: 1966, almost entirely live in the studio, with several of the songs being captured in a single take.

In November 1966, Mark Abramson directed a promotional film for the lead single "Break On Through (To the Other Side)." In hindsight this has been seen as a significant advance toward the development of the music video phenomenon.

To promote the single, the Doors made their television debut on a Los Angeles TV show called Boss City, circa 1966, possibly early 1967 and then on a Los Angeles TV show called Shebang, miming to "Break On Through," on New Years 1967. This clip has never been officially released by the Doors but can be seen on YouTube.

The second single, "Light My Fire," became a smash hit after its release in June 1967, selling 1 million copies and reaching #1 on the Billboard Charts on July 29th, keeping the top spot for three weeks. It established the group — in the vein of The Byrds and Jefferson Airplane — as one of America's counterculture bands. For AM radio airplay, the long middle organ and guitar solos were cut from the song making it 2:52 instead of the 6:50 original. Today, the song is played in its entirety on the radio.

(from en.wikipedia.org)