Released the same year as the equally pivotal Stained Class, Killing Machine cemented Judas Priest's standing and reputation as the world's foremost metal band of the late 1970s. Further diversifying its music and sporting increased confidence, boldness, and full-bodied songwriting, the album managed a then-unprecedented task of appealing to mainstream tastes via its impeccably solid production, creative prowess, and staggering melodies. Known in the United States as Hell Bent for Leather, Killing Machine remains a titanic release no matter the name. Mastered on Mobile Fidelity's world-renowned mastering system and pressed at RTI, this Silver Series numbered limited edition LP broadens the scope of the original production, helmed by none other than Pink Floyd The Wall producer James Guthrie. Besting those on all previous editions, the low-end thrust, high-frequency dynamics, and all-important midrange now come alive with unsurpassed detail and accuracy. Soundstaging and imaging positively explode before your eyes and ears, and instrumental separation allows insight into band's tight-fisted interplay. Recognizing the era's potential and pushing to expand metal's horizons, Priest created music that at the time hadn't any peer. With proto-metal luminaries Black Sabbath, Deep Purple, and Led Zeppelin experiencing career low points, and campy hard rockers following a softer path, the English quintet married street-bruising intensity to commercial accessibility without compromising any aggression, volatility, rawness, or ruggedness. Part of the success owes to Guthrie's expert hand. A majority, however, lies with the group's unrelenting ambition and variety—not to mention masterful performances. Exemplified in the breakthrough "Hell Bent for Leather," as tough-as-nails resilient as any metal song and delivered by vocalist Rob Halford with a pronounced ruffian attitude as guitars blaze behind him, Killing Machine sparks with high-powered muscle and concise, exact rhythmic structures. Halford comes into his own throughout, sending his falsetto into another universe on the wide-open highway-driving anthem "Evening Star," evoking deep loss on the ballad "Before the Dawn," and attacking "Delivering the Goods" as if he's a mercenary. There's not a wasted note or moment of doubt on the album. To author and metal expert Martin Popoff, music doesn't get any better. "To my mind, Killing Machine was the apex, the hallowed halls of heavy metal which Priest summarily occupied alone at this particular juncture in time," writes Popoff in his The Top 500 Heavy Metal Albums of All Time. "The songs on this record sweat the corners and creases of all of metal's characteristics, Priest firing on and off all speeds, from quick and note-dense to positively glacial."