Pope Sixtus I

Pope Sixtus I (also known as Xystus) was the sixth successor to Saint Peter as the Bishop of Rome of the Catholic Church. He served from approximately 116-125 C.E.
He decreed that the people should chant with the priest during the Sanctus at the Holy Communion section of the Catholic Mass.
He is considered a Saint by the Catholic Church. He died a martyr. His feast day is April 3 or 6.