Long before reunions became big-money pursuits, the key members of Deep Purple put aside differences that caused them to split in 1973 and, bowing not to financial concerns but public demand, reformed for their first album in 11 years and a subsequent blockbuster tour. While the record's title cleverly acknowledges the long time the musicians spent apart, everything about the LP confirms the inimitable blend of creative chemistry, crafty songwriting, and trademark skills shared by the five players. All the hallmark traits from Deep Purple's golden era (1970-1973) are on display throughout this platinum comeback affair, which has aged much better than most mid-80s efforts in terms of sound, performance, and content. At times mystical, aggressive, and dramatic, Perfect Strangers leaves a lasting impression courtesy of Ian Gillan's leather-lunged vocal range, Roger Glover's self-assured bass lines, Ian Paice's titanium-tough drumming, and the trade-off soloing between the wizard-like, vibrato-emboldened guitar playing of Ritchie Blackmore and voodoo-casting organ spells of Jon Lord. Compositions such as the hit ''Knocking at Your Back Door,'' hook-laden title track, and racing ''A Gypsy's Kiss'' could be deemed products of a supergroup. Yet calling them so shortchanges the artistry, as the posturing asides and attention-getting episodes common to such projects aren't here. Perfect Strangers is hard, heavy purity, the last album Deep Purple crafted of its kind - and one that stands right up to the ensemble's classic Fireball and Machine Head. Featuring dead-quiet surfaces, this Wax Cathedral LP is pressed at RTI.