The Books of Enoch — True Church Edition
2 Enoch 17
1In the midst of the heavens I saw armed soldiers, serving the Lord, with tympana and organs, with incessant voice, with sweet voice, with sweet and incessant (voice) and various singing, which it is impossible to describe, and (which) astonishes every mind, so wonderful and marvellous is the singing of those angels, and I was delighted listening to it.