Led by the remarkable bass voice of the late J.D. Sumner, the Stamps Quartet was a renowned gospel group best known for backing Elvis Presley. The group's history goes back to the '20s, but their most famous era came when Sumner left the Blackwood Brothers to manage and sing with them, ultimately taking top billing. They toured with Elvis from 1971 until his death in 1977, and Sumner's booming low notes were prominently featured. Now fronted by Ed Enoch from the Elvis days, the group continues and in 2015 claimed 91 years together, making them the longest-running male quartet in popular music.