I was with a couple of friends and one of them noticed something that startled them., She pointed to the direction this thing was at in the sky and it was very easy to spot. It was moving along very fast and was going in a straight line, that adjusted it's path, almost in a curve like manner, changing it's flight path behind the tree line. It seemed to be around 300 feet up and cruising along very quickly, around 400+ miles an hour and I tracked it for about 5 seconds.It was moving too fast to run into the house to get my camera, but I happened to have my trumpet in my hands, so I played a loud note towards it's direction to see if these things react to a directed sound. That was just prior to it changing direction, not if it's related or not, but those that want to do the math along how fast sound travels.I felt there was an intelligence flying it, not sure of it's origin and can only speculate. Friend had the same reaction, her statement was "that is not an airplane! Woah".This is my fourth sighting so it's not as startling to me to observe. Yet still, a little uneasy that something can fly through the local airspace with impunity. I think if more people observed the skies with more scrutiny they would notice more of these., I wouldn't have noticed myself since I was pre-occupied for this instance for example.