'New Song' in the Bible

They sang a new song, saying, "You are worthy to take the book, and to open its seals: for you were killed, and bought us for God with your blood, out of every tribe, language, people, and nation,

They sing a new song before the throne, and before the four living creatures and the elders. No one could learn the song except the one hundred forty-four thousand, those who had been redeemed out of the earth.