The Righteous Brothers
Their first major hit single was "You've Lost That Loving Feeling" in 1965. That song was produced by Phil Spector, and manifested Spector's Wall of Sound production techniques. They had several other hit singles during the 1960s, including a cover of "Unchained Melody" in 1965 and "(You're My) Soul and Inspiration" in 1966. In 1974, they scored another hit with "Rock and Roll Heaven", a paean to deceased rock singers.
"You've Lost That Lovin' Feeling" remains the most played song in radio history. It is estimated that it has been played over 8 million times to date.