The prevailing vibe at the tail end of the '60s was anything but peaceful or loving – not with the unending carnage of Vietnam, its terrors amplified by the Russian roulette of the draft lottery. Not with the Manson family metastasizing hippie idealism into unimaginable brutality. Not with the reflexive violence of Altamont, which would combine with the breakup of the Beatles to jeopardize that last vestige of '60s idealism, the notion of music as a sacred sanctuary, as the once-harmonious pop universe exploded into disparate factions, never to reconcile. Less than a month into 1970, America got its song for the asking – from a hearteningly familiar source – with the release of the immediately and perennially adored Bridge Over Troubled Water.

The title track offered that much needed message of hope with eloquent simplicity and grace. Opening the album, it gradually ascended from whispery intimacy to breathtaking grandeur on the wings of Art Garfunkel's greatest vocal. That brilliant example of slow-build aural architecture was but one of the record's myriad pleasures, not the least of which was the epic survivor's narrative, "The Boxer," a top 10 hit in 1969 and another of Paul Simon's most memorable songs. While several numbers, most notably "Cecilia," had nothing more pressing on their minds than getting to the hook, their old-school exuberance conspired to restore our faded memories of a long-ago moment when anything seemed possible – just what the doctor ordered for a generation whose golden dream had withered into its worst nightmare.

Ironically, during the making of this landmark work, which was universally embraced as a covenant of renewal, the duo was itself in the process of coming apart. Their diverging ambitions certainly had something to do with it. But more crucially, as with the Beatles before them, what for so many years had been a natural and unforced shared experience for the principals had become a strained, self-conscious one. Like the decade that had borne them into prominence, Simon & Garfunkel had run out of time. One could certainly make a case that, with "So Long, Frank Lloyd Wright," Simon was bidding adieu to his friend and partner, a onetime architecture major, or to the union itself, as, over a dusky bossa nova groove, Garfunkel sighed, "All of the nights we'd harmonize till dawn. / So long / So long."