Nashville's Richard Ferreira earns comparisons to Elvis Costello so often that the association borders on reflex reaction. But to flip the analogy, if Costello really were a blue-eyed soul singer, he'd sound more like Ferreira a better, less-strained vocalist, with a silky falsetto and a fiery tenor who crafts country soul á la mid-'70s Van Morrison and Arthur Alexander with such patience that he's yet to follow up on his under-appreciated 2002 album, Somewhereville. To reverse another common (and inaccurate) parallel, if Lucinda Williams grew up on Yo La Tengo ballads instead of Hank Williams blues, she'd sound something like Clare Burson, another Nashville resident who draws lightly on country and soul melodies to illuminate her dark, cloudy indie-rock supplications. Looking for the sleeper double bill of the summer? Ferreira and Burson might be the ticket.