One of the longest-running groups in country music, the Oak Ridge Boys started life as a gospel quartet before gradually modernizing their style and moving into secular country-pop. Yet even at the height of their popularity in the late '70s and early '80s -- when they were big enough to cross over to the pop charts -- their sound always remained deeply rooted in country gospel harmony. Their existence dates all the way back to World War II, circa 1942-1943, when a Knoxville, TN, group began performing gospel songs in nearby Oak Ridge, the home of an atomic bomb research facility. The group's members also performed in a larger aggregation called Wally Fowler & the Georgia Clodhoppers, which recorded for Capitol. However, lead singer Fowler decided to focus on gospel music in 1945. Dubbed the Oak Ridge Quartet, the group first appeared at the Grand Ole Opry that year and made their first recordings in 1947 with a lineup of Fowler, Lon "Deacon" Freeman, Curly Kinsey, and Johnny New.