German a cappella group Wise Guys were a most unlikely success story. Not only are a cappella groups a genuine rarity in the 21st century, but the barbershop-style quintet managed to attain remarkable commercial success in the German-language world, selling out concerts and releasing increasingly popular albums. It helped, of course, that the group sang amusing, often humorous pop songs that appropriated aspects of concurrently popular music, from rap and reggae to rock and techno, all the while singing entirely without musical instruments. The popularity of the Wise Guys reached an apex with Radio (2006), a concept album fashioned in the manner of a radio broadcast. ~ Jason Birchmeier