The day the temple was destroyed was the first day of the week
Due to the confusion the leviem started singing the fourth song, "Lord of vengeance is G-D, lord of vengeance appear"
There was hand to hand battle only feet away from them. The leviem had to meditate, block out all their senses and concentrate only on the song.
When the leviem would sing shira they would bind the various names of G-D that can be permuted from the words.
Had the leviem been able to finish, and reach the words, "Yatsmisam" binding the names of the Angels together, a mighty spirit of vengeance, Midas Hadin, would have come down.
The Romans would have never have been able to conquer the temple. They would have easily been defeated by the Jewish warriors.
The roman leaders knew the power of the Jews was dependent on the service. They therefore made it their priority to stop the shira.
The temple was the last battle, the Jewish resistance put all their remaining energy to protect it.
Due to our many sins we couldn’t hold them off. The Romans stopped the leviem on the second to last sentence.Meaning, the reason why they confused the song was to give them a chance, had the people repented they would have completed it.
"May G-D avenge the blood of his nation"