The proper (Latin proprium) is a part of the Christian liturgy that varies according to the date, either representing an observance within the liturgical year, or of a particular saint or significant event. The term is used in contrast to the ordinary, which is that part of the liturgy that is reasonably constant, or at least selected without regard to date, or to the common, which contains those parts of the liturgy that are common to an entire category of saints, such as apostles or martyrs.
The proper of the mass, strictly speaking, consists of the Introit, Gradual, Alleluia or Tract, Sequence, Offertory, and Communion - in other words, all the variable portions of a mass which are spoken or sung by the choir or the people. These are sometimes called the "minor propers" to distinguish them from the collect, secret, postcommunion, and readings - in other words, all the variable portions of a mass which are spoken or sung by the priest or other attendants, such as a lector or deacon. In Roman Catholic and Anglo-Catholic practice, there is a moveable portion of the service that, strictly speaking, does not form part of the proper known as the Accentus. Portions of the Accentus are often referred to as part of the "proper" if they satisfy the criteria of changing by date (such as the Preface and Epistle).
At the little hours the propers normally include only the troparion and kontakion of the day, but during great lent include paroemia as well as hymns which vary according to the day of the week. Three times a year the longest form of the little hours, the Royal Hours, are celebrated which have propers that include particular psalms, hymns (stichera), paroemia, and Epistle and Gospel readings.
At compline the propers are the troparia and a canon in honour of the Theotokos (one of 56, there being for each day of the week for each of the eight tones in the Octoechos); however, if the normal daily service to a saint is displaced by some other commemoration, e.g., another more recently canonized or a locally commemorated saint or whatnot, the displaced saint's service is sung at compline, consisting of the saint's canon followed by the stichera appointed for "Lord, I have cried" at vespers. During the first week of Great Lent, the "Great Canon" of Saint Andrew of Crete is divided into four parts, with a part sung each night (Monday through Thursday).
When there is no celebration of the divine liturgy (or when the divine liturgy is combined with vespers), the typica is performed in its stead, its propers including the troparia which would have been read at the third antiphon of the liturgy, the prokeimenon, Epistle, Gospel, and kontakia.
At the divine liturgy propers include the antiphons, troparia, kontakia, prokeimena, the readings from the Apostle and Gospel, the megalynarion (hymn replacing It is Truly Meet, not to be confused with the megalynarion at Matins) and the communion hymn.
Ending every service (or at the end of an aggregate of services), the priest says a dismissal (final blessing) which differs according to the day of the week. These are of two kinds: the lesser or greater dismissal, the latter mentioning more saints, including the saints of the day and at the end of the divine liturgy also mentions the name of the saint who composed the liturgy. Special dismissals used during holy week and great feasts of the Lord.
The propers can be found in the following liturgical books:
As well as a number of individually published services or collections and, at least in large monasteries, compilations of patristic writings.