Old English riddle

My dress is silent when I tread the ground 
Or stay at home or stir upon the waters.
Sometimes my trappings and the lofty air
Raise me above the dwelling-place of men,
And then the power of clouds carries me far
Above the people; and my ornaments
Loudly resound, send forth a melody
And clearly sing, when I am not in touch
With earth or water, but a flying spirit.