The Fifth Dimension's unique sound lay somewhere between smooth, elegant soul and straightforward, adult-oriented pop, often with a distinct flower-power vibe. Although they appealed more to mainstream listeners than to a hip, hardcore R&B audience, they had a definite ear for contemporary trends; their selection of material helped kickstart the notable songwriting careers of Jimmy Webb and Laura Nyro, and their biggest hit was a medley from the hippie musical Hair, "Aquarius/Let the Sunshine In." The group's soaring, seamless harmonies were given appropriately sweeping, orche...