Complex sentence: Danny formed the Happy Valley Boys after Charlie joined the military in 1941 and in 1944 the Happy Valley Boys relocated to Nashville where they became members of the Grand Ole Opry and also made regular appearances on WSM radio in Nashville.
Split into simpler sentences: Danny formed the Happy Valley Boys after Charlie joined the military in 1941. In 1944 the Happy Valley Boys relocated to Nashville, where they became members of the Grand Ole Opry, and also made regular appearances on WSM radio in Nashville.