Beata Viscera composed by Perotin (fl. c. 1200). Performed by Early Music New York under the direction of Frederick Renz on their album "A Medieval Christmas".

Ex cathedra Records available at:
EarlyMusicNY.org
http://earlymusicny.org/excathedra.php
CD Baby
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and Amazon
http://amzn.to/186aSok