Riddle

Hovering above, plummeting below Takes wings again, then comes out low Riding the air, drawn by the Earth Dealing in disgrace, spilling with mirth Ever a-changing, always the same Sits still, alone and still basking in fame Inside the darkness it gives flaring light But when you look within, you'll only see the night Agrees with you when you say something wrong And with your own words it rights (Writes) you (A song) You'll only find out it's not what it appears Blasts your mind's gates with words, sieging your ears In case this riddle doesn't make much sense Look inside my soul and you'll see my defense I'll only ask you what do you see It's nothing, but a frightful harmony