The angels can know us more intimately and love us when we sing, and they are not asking that we sound like the Philharmonic. They ask us simply to sing because we are harmonic. We are symphonic and in these ways we can connect with the angelic world. I think and feel that the angels wait for us at every given moment. If we alternate song and silence, consciously, with burning attention, every rounded tone carves out the possibility to bridge heaven and earth, to live the material half of the angel.
Angels are evidence that God is taking notice of us. They ask the same always: surrender, obedience, submission, and humility before the Holy One. Some say they make us homesick for heaven.