Within this framework, Fr. Crichton discusses in detail, and critically, the New Order of the Mass, the reform of the Roman Calendar, the style, intentions and content of the new Roman Missal. His explanations are concise, perceptive, often witty and always informative. He writes from a background of long reflection on the liturgy, deep and lifelong study of it, and equally lifelong parish experience in bringing the liturgy to the people. He has been able to combine, in Christian Celebration: The Mass, a book about what the liturgy is: its what and why, with a practical guide on what has been happening in the liturgy of the Roman Rite on the last few years, and what this means in terms of parish worship: the how.