Half a century ago, six choral scholars at King’s College Cambridge formed their own choir. They took a bold approach, rewriting the rules about what classically trained vocal ensembles could sing and how they could sing it, mixing the contemporary with the classical and the sacred with the secular. During the last fifty years, twenty-six King’s Singers have come and gone, but they have all had in common a democratic musical sensibility and consummate technique, as much at home with Byrd as with the Beatles. “The King’s Singers have the same microscopic perfection one sometimes hears from purely instrumental chamber musicians,” declares The Washington Post. For their fiftieth anniversary the King’s Singers dazzle with a typically wide-ranging program. They begin with an anniversary commission from former member Bob Chilcott before moving back in time to renaissance and romantic compositions. They surprise with a set of spirituals that includes arrangements of U2 and Paul Simon and end the night’s first half with a new commission by firebrand composer Nico Muhly. The concert closes with a panoply of audience favorites and new arrangements.