Elvis Presley's "Just Because" gets its revved-up jangle from Bill Monroe, and the father of bluegrass' uptempo influence can still be heard in later rock chart-toppers like Mumford & Sons. Monroe's sparkling mandolin timbre is reflected in David Grisman's soloing throughout the Grateful Dead's "Friend of the Devil," and his swift, polished style oiled The Dillards, Ricky Skaggs, and countless other string bands.