'Instruments' in the Bible

And a voice from heaven came to my ears, like the sound of great waters, and the sound of loud thunder: and the voice which came to me was like the sound of players, playing on instruments of music.

And I saw a sea which seemed like glass mixed with fire; and those who had overcome the beast and his image and the number of his name, were in their places by the sea of glass, with God's instruments of music in their hands.