From PapalMusic comes this up-to-the-minute recording of the famous Allegri piece usually heard during Holy Week. You will find this version interesting because it lacks that over-the-top drama of the High C from the treble but instead places it in the tenor part in a comfortable range. This is said to be a more authentic version. Maybe someone knows more.
It is also great to see the singing of Audi Benigne Conditor, a beautiful Lenten hymn that any parish can pick up:
Also, the Gregorian introit for the day:
We are so blessed!!