Low flying disc shaped object with colored lights at it's base changing in and out or maybe rotating, quiet, serene.

I was actually raised in a small rural town East of Ashland. While growing up, two siblings and myself shared a bedroom. I'm not exactly sure of the year, but I know my older sister was married and my other sister was married in 1973. I finally had my own bedroom. My brother was still @ home and sleeping. Mom and Dad of course were sleeping in their room. I would have been 20 years old @ the time. A bedroom window was over my bed. To the north of the house was a Maple tree which was outside my bedroom window. Early morning. Still dark outside. Clear sky.
 I was awoken by a very loud sound, that sounded like a low airplane. I wanted to see what the sound was so I got up on my knees and looked outside the window. What I saw has stayed with me for 33 years. Just above the tree-top was a disc shaped object that had colored lights at it's base. The lights seemed to have a pattern of rhythm changing in and out or maybe rotating.  It slowly moved just above the tree top heading north. I cannot remember a deafening loud noise at my window then, but a humm sound. It was summer. There was no motion of the leaves or tree limbs (like strong wind) when it passed over. I lost sight of it after it passed over the tree. I ran into the bathroom (which was the next room over)to look out that window (which faced the same direction) and it was gone. It's like it totally disappeared quickly.
 What's amazing to me is nobody else in the house was awoken by the LOUD noise. It's like I was the only one meant to see it.
 My brother, maybe 10 minutes later was up. I said to him, "I just saw a UFO". His response was naturally...yea right!  This is not a young girl's imagination. This was not a dream. I KNOW WHAT I SAW and I will never forget it!
Witness indicates that the date of the sighting is approximate.  PD