'This book, a classic guide to the celebration of the Church's ancient Gregorian Rite in the English-speaking world, will serve priests and seminarians of the twenty-first centuryGC ?o just as it served so many priests of the twentiethGC ?o in their pastoral mission, which now necessarily includes familiarity with and openness to the use of the older form of the sacred liturgy. I happily commend it to the clergy, seminarians and laity as a reliable tool for the preparation and celebration of the liturgical rites authoritatively granted by the Holy Father in Summorum Pontificum . 'I congratulate the