This hillbilly brother act was a major influence on both the Louvins and the Everly Brothers, playing guitar and mandolin-backed mountain songs with simple harmonies. Their perfectly matched voices blended together with seamless beauty, creating a gut-wrenchingly forlorn sound. With the wonderfully crackling backdrop of '30s and '40s-era recordings, Blue Sky Boys will reduce you to a puddle of tears as they sing about mothers searching for wayward sons and star-crossed lovers driven to murder.