sentences:  Lost for more than 400 years, it was recently rediscovered in Paris.Most of the mass is for five separate choirs of 8 voices each, with the closing Agnus Dei being for five separate choirs of 12 voices each; all of the voice parts are fully independent.With its huge polychoral forces, climaxing on sixty fully independent parts, it is the largest known polyphonic composition from the entire era.