Revelation 14:1-3

Then I looked, and behold, the Lamb was standing on Mount Zion, and with Him 144,000 who had His name and the name of His Father written on their foreheads.

And I heard a voice from heaven, like the sound of many waters and like the sound of loud thunder, and the voice which I heard was like the sound of harpists playing on their harps.

And they *sang a new song before the throne and before the four living creatures and the elders; and no one was able to learn the song except the 144,000 who had been purchased from the earth.