Complex sentence: The band was The Rocky Mountaineers, led by a young singer named Leonard Slye--later known as Roy Rogers-who after listening to the tall, slender, tanned Nolan sing and yodel, hired Nolan on the spot.
Split into simpler sentences: The band was The Rocky Mountaineers, led by a young singer named Leonard Slye--who would later change his name to Roy Rogers. After listening to the tall, slender, tanned Nolan sing and yodel, Slye hired Nolan on the spot.