Mastered from the original analog tapes, Mobile Fidelity's numbered-edition hybrid SACD helps take One of These Nights to new limits. Playing with reference sonics and incredible clarity, it provides a rich, dynamic, transparent, and three-dimensional view into a release that moved country-rock ahead by leaps and bounds – and paved the way for the Eagles' ascendancy to global superstardom. The opportunity to zero in on the particulars of the Eagles' golden harmonies, distinct vocal timbres, and cohesive interplay has never been better. Everything about the record continues to resonate and connect with multiple generations, including the striking cover art.

Devised by West Texas artist Boyd Elder, the now-familiar skull-and-feathers themed piece that graces the front of One of These Nights represents where the Eagles have been and where they were going. Album art director Gary Burden explained: "The cow skull is pure cowboy, folk, the decorations are American Indian-inspired, and the future is represented by the more polished reflective glass beaded surfaces covering the skull." Moreover, Elder met the group years earlier when Henley and company performed at one of his gallery openings in California. MoFi's UD1S box set allows Elder's vision, and Burden's debossed treatment, to pop and appear as if it was a standalone object.

Of course, what's inside the sleeve proves equally compelling. Though One of These Nights marks the final appearance of band co-founder Bernie Leadon on an Eagles LP and contains three of his tunes, the record's tremendous success owes to Frey and Henley's timeless contributions. Taking the next step in their maturation and evolution, the pair crafted several songs while living together as roommates in a rented house in which they converted a music room into a recording studio.

The duo's bond and chemistry pulse throughout the record – particularly in the tight arrangements, tasteful instrumental flourishes, and seamless blending of the folk, country, and rock elements. The musical combinations and partnership not only produced the Eagles' first million-selling single (the slow-dancing "Take It to the Limit," co-written with bassist-vocalist Randy Meisner) and the Frey-led cheating classic "Lyin' Eyes," but the famed title track, which nods to the era's nascent disco scene as well as Kenneth Gamble and Leon Huff's Philly soul platters.

Frey named "One of These Nights" as his favorite Eagles composition of all-time; Meisner's high harmonies alone send the track into a galaxy of its own. Speaking of the latter, Leadon's instrumental "Journey of the Sorcerer" ventures into another universe and was soon used by Douglas Adams as the theme to his "The Hitchhiker's Guide to the Galaxy" radio series. Inspiration and creative experimentation also dragged the Eagles into the blues. Another Frey-Henley gem, the self-probing "After the Thrill Is Gone" serves as a response song to B.B. King's signature track and more evidence the band was turning the lens inward for lyrical narratives. Like everything on One of These Nights, the song confirms the Eagles were breathing rare musical air.