Eldorado (subtitled A Symphony by the Electric Light Orchestra) is the fourth studio album by the Electric Light Orchestra (ELO). It was released in the United States in September 1974 by United Artists Records and in the United Kingdom in October 1974 by Warner Bros. Records.

Eldorado is the first complete ELO concept album; bandleader Jeff Lynne conceived the storyline before he wrote any music.^[2] The plot follows a Walter Mitty-like character who journeys into fantasy worlds via dreams, to escape the disillusionment of his mundane reality. Lynne began to write the album in response to criticisms from his father, a classical music lover, who said that Electric Light Orchestra's repertoire "had no tune".^[3] The influence of The Beatles is prevalent, especially in the melody of the verse of "Mister Kingdom" which to some degree resembles the Beatles' "Across the Universe".^{[citation needed]}

Eldorado marks the first album on which Jeff Lynne hired an orchestra; on previous albums band members would play strings using multitracked overdubbing.^[2] Louis Clark co-arranged, with Lynne (and keyboardist Richard Tandy), and conducted the strings. The group's three resident string players continued to perform on recordings, however, and can be heard most prominently on the songs "Boy Blue" and "Laredo Tornado". Mike de Albuquerque departed early on in the recording process, as touring made him feel separated from his family. Lynne plays most of, if not all, the bass tracks and backing vocals for the album, but de Albuquerque still featured on the final release as well as getting credited. Kelly Groucutt replaced him for the subsequent tour, when cellist Melvyn Gale also joined (replacing the departing Mike Edwards). "Eldorado Finale" is heavily orchestrated, much like "Eldorado Overture". Jeff Lynne said of the song, "I like the heavy chords and the slightly daft ending, where you hear the double bass players packing up their basses, because they wouldn't play another millisecond past the allotted moment."^{[2][verification needed]}

The cover, designed by John Kehe, is a mirrored still frame of Dorothy's ruby slippers from the 1939 movie The Wizard of Oz.^[4]

• Jeff Lynne – lead & backing vocals, electric & acoustic guitars, bass, Moog, production, orchestra & choral arrangements
• Bev Bevan – drums, percussion
• Richard Tandy – piano, Moog, clavinet, Wurlitzer electric piano, guitar, backing vocals, orchestra & choral arrangements
• Mike de Albuquerque – bass & backing vocals (credited; departed during the recording of the album)
• Mike Edwards – cello
• Mik Kaminski – violin
• Hugh McDowell – cello

Additional personnel

• Peter Forbes-Robertson – spoken word
• Louis Clark – orchestra and choral arrangements and conducting
• Al Quaglieri – reissue producer (2001)