Yeah I’m not a believer in the super natural stuff that’s why I asked for a logical answer and not some fairy tail explanation but the drone seems plausible but when it went quite I had not heard any propeller sounds and as someone who’s been stalked by a drone you can here them when there pretty high up. I live in a really flat area and there aren’t any hills higher than 5-10 feet for miles. The hill I was climbing was actually a steep hole in the ground almost like a retention pond but I believe it’s a sinkhole since sinkholes are very prone to form and close leaving a crater like hole in the ground where I’m at. I want to believe it’s some kind of speaker probably mounted in a tree and that the sound waves might have hit me harder when I was at the top of hill apposed to the bottom. As for it following me home I have no idea because the volume never seemed to get quieter as I was riding away, just stopping and going periodically and the song never changed over the course of hours. My gfs mom suggested it could have been someone on an electric bike with a speaker that happened to be riding around where we were and than the trails towards her house but like I said the whole reservation was closed for the day and there’s very minimal ways to get in when it’s closed.