Revelation 14:1 (WEB)
I saw, and behold, the lamb standing on Mount Zion, and with him one hundred forty-four thousand, having his name and the name of his Father written on their foreheads.
Revelation 14:2 (KJV)
I heard a sound from heaven like the sound of many waters and like the sound of a great thunder. The sound I heard was like that of harpists playing on their harps.
Revelation 14:3, 3 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. - WEB