And whilst they were at supper, Jesus took bread, and blessed, and broke: and gave to his disciples, and said: Take ye, and eat. This is my body. And taking the chalice, he gave thanks, and gave to them, saying: Drink ye all of this. 28 For this is my blood of the new testament, which shall be shed for many unto remission of sins. And I say to you, I will not drink from henceforth of this fruit of the vine, until that day when I shall drink it with you new in the kingdom of my Father. And a hymn being said, they went out unto mount Olivet.
*Yeah, I know I'm going out on a limb but I going to "assume" he sang...
....., and also assuming that he sang 12th Century plain chant
*No. I am asseting He sang in a manner you might recognise as plain chant. Of course it was a Christian organic development risen out of the chanting down in the Synagogue.
THe Catholic Mass is straight from the Bibe and many of our acts of Worship are echoes of Synagogal worship