The church generally has three sets of bells: the tower bells, the Sanctus or sacring bells, and the sacristy bell.
The tower bell or bells are rung before the beginning of a liturgy. The English Prayer Book from 1552 onwards directs that “the Curate that ministreth in every Parish Churche or Chapell, beyng at home, and not beyng otherwise reasonably letted, shall say [Morning and Evening Prayer] in the Parishe Churche or Chapell where he ministreth, and shall tolle a belle thereto, a convenient tyme before he begyn, that suche as be disposed maye come to heare Goddes worde, and to praie with hym.”
In England that often means that the bell is rung for five minutes one half hour before public service and then again for the five minutes immediately before. The tower bell also is traditionally tolled solemnly for funerals and joyfully after weddings and on other joyous liturgical or public occasions.
The Sanctus Bell (so called because it is rung during the Sanctus at the Eucharist) varies in character: it may be a small silver bell (especially for a bishop), a group of bells (campanili), a gong, or a switch connected to the tower bell. The Sanctus Bells are rung during the liturgy to call attention to an important moment. This was particularly important in the pre-Vatican II Latin rite in the Roman Church, when the liturgy was largely said in an inaudible voice by the priest in a language not understood by most of the congregation.
The bells are used even when the liturgy is in English in many places because people’s attention does tend to wander. When a priest is celebrant, the bells are rung: three times at the beginning of the Sanctus, during the Canon at the genuflections and elevations at the consecration of the Host and chalice, when the priest says ‘Lord, I am not worthy’ before his own communion, and when the priest says,’Behold, the Lamb of God’ as a signal for the communicants to come to the altar rail. When a bishop celebrates these bells are only rung at the consecrations in the Canon.
The sacristy bell is rung as a signal that the priest is about to enter the sanctuary from the sacristy. It is a signal for the congregation to stand.
Bells in Holy Week
In Holy Week the bells are rung after the intonation of the Gloria in excelsis on Maundy Thursday and then are silent until the intonation of the Gloria on Holy Saturday. (No musical instruments are played in church during that same period.) During this time of silence a wooden clacker may be used instead of bells. On Holy Saturday at the Easter Vigil after the intonation of the Gloria all of the bells in the church are rung joyfully to signal the beginning of Easter and the Passiontide veils are removed before the Gloria resumes.