Revelation 14:2 in the King James Version
And I heard a voice from heaven, as the voice of many waters, and as the voice of a great thunder: and I heard the voice of harpers harping with their harps:
Context
1 I saw, and behold, the Lamb standing on Mount Zion, and with him a number, one hundred forty-four thousand, having his name and the name of his Father written on their foreheads.
2 I heard a sound from heaven like the sound of many waters and like the sound of a great thunder. The sound which I heard was like that of harpists playing on their harps.
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.