It's been a long time since Iron Maiden put out an album virtually all their fans could agree was stellar. That album was their semi-conceptual triumph, Seventh Son of a Seventh Son, which was released on April 11, 1988.

Iron Maiden’s career built from strength to strength, Ever since Iron Maiden’s 1980 eponymous LP had proclaimed the New Wave of British Heavy Metal’s arrival, followed closely by 1981’s fearsome Killers. They accelerated toward worldwide success after the arrival of singer Bruce Dickinson, thanks to a remarkable streak of blockbuster metal albums in 1982’s The Number of the Beast, 1983’s Piece of Mind and 1984’s Powerslave. It finally culminated in the decade-defining double live album that was 1985’s Live After Death.

And then the unthinkable happened: Iron Maiden stumbled. The future-themed Somewhere in Time, from 1986, was the work of a group fried to a crisp after a grueling half-decade’s worth of album-tour-album-tour cycles. While Somewhere in Time sold somewhat consistently based on sheer momentum and "Wasted Years," guitarist Adrian Smith’s difference-making hit, critics and cynics alike greedily got their knives out to skewer the band.

So, when time came to get to work on Iron Maiden’s seventh studio album, even ever-confident bassist and band leader Steve Harris was probably feeling some heat to deliver another unqualified heavy metal triumph.

Listen to Iron Maiden's 'Seventh Son of a Seventh Son'

He turned to Dickinson and Smith to collaborate on their new compositions like never before, churning out a slew of powerful anthems loosely based around the seventh-son folklore that proved inspired, infectious and unmistakably Iron Maiden.

In "Moonchild" and "The Evil that Men Do," the band delivered galloping warhorses for the metal faithful; in the epic title track and ‘Infinite Dreams,’ progressive ideas that constantly pushed their songwriting envelope; in “The Clairvoyant” and “Only the Good Die Young,” beyond-solid album cuts advancing the conceptual plot-line; and in "Can I Play With Madness," that requisite hit single perfect for radio airplay. Even guitar player Dave Murray contributed a rare song in “The Prophecy,” a majestic number concluding with whimsical acoustic guitars.

Perhaps most incredible of all was the album’s generous use of synthesizers for the first time in Iron Maiden’s career; but because these were used as backdrops and tonal colors surrounding the band’s once again crunchy, distorted guitar sound (unlike the guitar-synths that muddled Somewhere in Time), they produced no ill effects on the end product or the band’s reputation – further evidence the material was of the highest metallic caliber.

Sure enough, Seventh Son of a Seventh Son entered the British charts at No. 1. While U.S. audiences would only take a shine to the album over a long period of time, by summer’s end Iron Maiden were donning their heavy-metal crown once again as they headlined the Castle Donington Monsters of Rock festival.

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