Angels are always dynamic. They are constantly moving. Angels play the harp. In size, their harps are small. Their harps do not have as many strings as the harps that we have.
Angels do sing, but they are more oriented towards instrumental performance.
They like music more than words and melodies. Some angels are closer to God, so they see him more often. All angels have free access to God. Unless there is an emergency, they will not disturb him, because they know how busy is his schedule. Archangels are the leaders of all the angels.