The Temptations were the most successful R&B vocal group of the 1960s, their popularity rivaled only by Curtis Mayfield and the Impressions. Despite several stylistic and line up changes (lead singers Eddie Kendricks and David Ruffin both went on to solo careers), The Temptations scored hit after hit throughout the decade. In addition to mastering the smooth R&B ballad, the group pioneered a brand of tough, rock-influenced soul music that inspired scores of later artists.