Airs Sunday, December 25, at 7 p.m. Celebrate Christmas with the sound of soaring voices. Stile Antico, the award-winning choir from London, pays a visit to St. Paul's Church on Harvard Square for a concert of radiant sacred music for the Christmas season by the most acclaimed composers of the renaissance. Hear the group's luminous blend of voices sing the intricately woven music of Thomas Tallis and William Byrd. Hosted by Cathy Fuller of WGBH.