Josh Groban's fifth studio album, 2010's Illuminati ons, finds the vocalist working with songs informed as much by American roots music as by the classical crossover sound he helped popularize. Featuring production from famed producer Rick Rubin (Red Hot Chili Peppers, Johnny Cash, Metallica), the album includes many Groban originals, some of which were co-written with former Semisonic frontman and Dixie Chicks collaborator Dan Wilson. Also lending their talents here are such luminaries as guitarist Smokey Hormel, organist Spooner Oldham, arrangers David Campbell and James Newton Howard, Brazilian star Carlinhos Brown, and others.,