Sarah McLachlan's vivid piano-driven balladry is a benchmark for legions of singer/songwriters, her otherworldly voice and passionate instrumentation fueling Beth Orton's dreamy folk, Dido's ethereal vocals, and Sara Bareilles' nimble storytelling. But her influence on pop's brightest can't be overstated either, with Nelly Furtado and Florence Welch taking their cues from McLachlan's melodic grooves.