If it seems like Nashville’s well of talented singer-songwriters is never-ending, that’s probably because it is. And Mercy Bell, living in Music City by way of Boston and New York City, is another distinct voice with a potent, progressive take on emotive, modern folk. It’s a perspective clear on her new song “Home,” where Bell confesses to the coping mechanisms that have let her avoid life’s harshest moments, and a path to redemption that’s better late than never.