Blue Heron: The Lost Music of Canterbury Music Before 1800 Corpus Christi Church February 10, 2019 Sequenza 21  By Christian Carey NEW YORK – On February 10th, the Boston-based early music ensemble Blue Heron made one of its regular appearances at the Music Before 1800 series at Corpus Christi Church in Morningside Heights. Directed by Scott Metcalfe, an ensemble of a dozen vocalists performed five selections, all votive antiphons, from the Peterhouse Partbooks.  Copied by John Bull during the reign of Henry VIII, the partbooks now reside at Peterhouse College of Cambridge University. The tenor book is missing, as are