If you attended last Saturday's Worcester Chorus Concert: Bach's B Minor Mass and went down to Washburn Hall for intermission, you probably witnessed a group of teenagers performing a very quirky rendition to the Queen song "We Will Rock You, " appropriately renamed "We Will Bach You." This performance included harmonies, rapping, and body drumming, as well as beautiful gospel vocals from a young woman who is visually impaired. This group of kids, students and alumni from Fitchburg High School, are part of a group called The Tribe, led by singer/songwriter Wil Darcangelo.