Clarkston A Cappella group Detroit Voice performs a special concert at 8 p.m. on May 1 at Clarkston Junior High’s auditorium. The group is collaborating with University of Michigan A Cappella group Amazin’ Blue, of which Clarkston schools and Detroit Voice alumna Mason Van Gieson is a member. Concert tickets will be available at the door, $3 for students and $7 for adults, free for children under 10.