This is the album where Jeff Lynne finally found the sound he'd wanted since co-founding Electric Light Orchestra three years earlier. Up to this point, most of the group's music had been self-contained – Lynne, Richard Tandy, et al., providing whatever was needed, vocally or instrumentally, even if it meant overdubbing their work layer upon layer. Lynne saw the limitations of this process, however, and opted for the presence of an orchestra – it was only 30 pieces, but the result was a much richer musical palette than the group had ever had to work with, and their most ambitious and successful record up to that time. Indeed, Eldorado was strongly reminiscent in some ways of Sgt. Pepper's Lonely Hearts Club Band.
Electric Light Orchestra's third album showed a marked advancement, with a fuller, more cohesive sound from the band as a whole and major improvements in Jeff Lynne's singing and songwriting. This is where the band took on its familiar sound, Lynne's voice suddenly showing an attractive expressiveness reminiscent of John Lennon in his early solo years, and also sporting a convincing white British soulful quality that was utterly lacking earlier. The group also plugged the holes that made its work seem so close to being ragged on those earlier records. "Showdown" and "Ma-Ma-Ma Belle" (the latter featuring Marc Bolan on double lead guitar with Lynne) became AM radio fixtures while "Daybreaker" became a concert opener for the group and, along with "In the Hall of the Mountain King," kept the group's FM/art rock credentials in order.
Cut during the fall of 1972, Electric Light Orchestra II was where Jeff Lynne started rebuilding the sound of Electric Light Orchestra following the departure of Roy Wood from the original lineup. It was as personal an effort as Lynne had ever made in music, showcasing his work as singer, songwriter, guitarist, sometime synthesizer player, and producer, and it is more focused than its predecessor but also retains some of the earlier album's lean textures. Lynne, drummer Bev Bevan, bassist Mike D'Albuquerque, and keyboardist Richard Tandy comprise the core of the band, with two cellists and a violinist sawing away around them.
Although ELO quickly became Jeff Lynne's baby, it was launched as a collaboration between Lynne and his bandmates in the Move, multi-instrumentalist Roy Wood, and drummer Bev Bevan. Indeed, the label on ELO's first album reads "Move Enterprises Ltd. presents the services of the Electric Light Orchestra," and most histories claim that the initial idea for the spin-off group combining rock and classical music was Wood's, not Lynne's. Wood and Lynne split the songwriting duties on Electric Light Orchestra, much as they did on late-period Move albums, but it seems like their visions of what ELO was were widely divergent. Wood's songs are clearly more classically influenced, with the string and horn sections driving the songs rather than merely coloring them, as they do on Lynne's tunes.