On one level, Electric Light Orchestra’s Eldorado (1974) is about a quest for “the key to the eternal dream” just beyond reach. But it’s also very much about band leader Jeff Lynne’s own quest to fuse rock and classical music forms into an artistically valid whole. Decked out in sumptuous arrangements, its tracks are filled with scurrying harps, massed guitars, and cooing choruses, invoking the grandeur of a 1930s film soundtrack. Lynne escorts the listener through this dazzling tableau, singing with John Lennonesque dreaminess and wonder. Beneath all the baroque pomp beats a rock ’n’ roll heart, as evidenced by the bluesy “Nobody’s Child,” the ’50s-flavored “Illusions In G Major,” and the Dylanish “Poor Boy (The Greenwood).” Lynne and his bandmates indulge their orchestral fantasies fully during the album’s “Overture” and “Finale.” Reining in the flourishes, they deliver “Can’t Get It Out Of My Head,” a natural hit single. ELO whipped up a gorgeous layer cake of an album with Eldorado, spooning lush symphonic icing over solid pop/rock rhythms. It remains a richly enticing treat.