The Triduum begins on Holy Thursday.
There is one Mass this day…the Mass of the Lord’s Supper. It is a beautiful Mass with the Washing of the Feet of the 12 (12 people representing the Apostles) and at the conclusion of the Mass, we sing the Pange Lingua and have the transference to the Altar of Repose of the Eucharist. This is where one can spend an hour in prayer with the Exposed Eucharist in a location somewhere near the main sanctuary (a chapel, an Adoration room, or some other suitable place) that has been decorated to recall the Garden of Gethsemane. Many churches leave the host exposed for Adoration until Midnight or later. This recalls the request of Jesus for the Apostles to stay awake one hour with him to pray before He was led away to be put on trial.
Not a Holy Day of obligation, but a most beautiful Mass, and the commemoration of the institution of the Holy Eucharist. It’s a wonderful thing to go to this Mass.
On Good Friday there is no Mass. The tabernacle is empty. Jesus is not there. The tabernacle door is left standing open. It’s a very sad thing to see this. It really makes you stop and think. No genuflecting when you enter for this reason, although many people do out of habit. (Jesus at this point is being crucified) There may be Stations of the Cross at 3 PM, and also a Communion Service with the reading of the Passion as well, perhaps in the evening. At the beginning the Priests, Deacons, and acolytes prostrate themselves before the altar. Typically there is no singing except for the Psalm and the Reproaches. The reproaches may be sung during the Veneration of the Cross. For the Veneration, people get in line as they do for communion, and they come forward to kiss the cross. A lovely and moving thing to participate in. Holy Communion is offered using the pre-consecrated hosts, as the previous poster said. (Same hosts that were reposed the evening before). Attendees leave in silence.
Not a Holy day of Obligation, but a moving and beautiful service.
The Holy Saturday Vigil Mass is the Mass which begins at dark. The Easter fire is lit, and the new Easter candle is lit from it. Many small candles held by the faithful are lit from the new flame and the Candle is dipped in the Holy Water 3 times. There are many symbolic and beautiful images at this Mass. There are 7 readings that illuminate the history of our faith, beginning with the creation story along with our small hand held candles. The Gloria is sung again, and the lights come up! After not singing Alleluia for so long, a flurry of Alleluias ring out before the Gospel. After the Homily, those who are to be baptized and welcomed into the faith begin. Then come the Confirmations. Mass continues as usual, and if there are any First Communions, they happen, and then the entire congregation receives Communion. It’s a long GLORIOIUS Mass and something that everyone should attend if possible. Many people are not able to participate in such a lengthy liturgy, but if you are able to, it’s fabulous. If you are in RCIA, this is your big day!
Congratulations, many many blessings!