Employing Calexico’s Joey Burns as producer and using Calexico’s Arizona recording studio brings new sonic textures to tried and true Philly singer-songwriter Amos Lee. Mission Bell is one of his more focused albums and with the careful addition of Lucinda Williams on “Clear Blue Eyes” and Willie Nelson on “Behind Me Now” and “El Camino (Reprise),” Lee has the variation his work calls out for. Not that Lee can’t carry things on his own. The literate desperation of “Stay With Me” and “Out of the Cold” ache with just the right touch of soul-searching that underpins the clear spiritual quest of the tougher street funk of “Jesus” and the chill-inducing “Violin.” As a singer, Lee carries country, folk, blues, gospel and soul all with equal authority. The harmonies support his loner streak with just the right amount of help to get him to the next verse. “Hello Again” graces the lite-FM part of the dial that may help him crossover beyond his dedicated followers.