'New Song' in the Bible

They were singing a new song: "You are worthy to take the scroll and to open its seals because you were killed, and at the cost of your own blood you have purchased for God persons from every tribe, language, people, and nation.

and they were singing a new song before the throne and before the four living creatures and the elders. No one was able to learn the song except the one hundred and forty-four thousand who had been redeemed from the earth.