'New Song' in the Bible

And they sang a new song, saying, You are worthy to take the book and to open its seals, for You were slain and have redeemed us to God by Your blood out of every kindred and tongue and people and nation.

And they sang as it were a new song before the throne and before the four living creatures and the elders. And no one could learn that song except the hundred and forty-four thousands who were redeemed from the earth.