Me and my friend Adam were at his house one day in a city called Hickory. It was his mother and father's house. They've lived there for awhile, everything seemed fine, it was a nice little house. On this day, it was around lunch time and we were just sitting there chatting to each other, we talked for a little while then we heard a knock on the door, Adam got up, answered it, it was his girlfriend, by this time now it's around 4 pm.
We decided to go to his bedroom to play his playstation 2, so we all went in there, it was a little room so I was on the bed, he was sitting in the floor and she was sitting in a fold down chair, now let me remind you that there are only three people in this house, one cat, one dog. Adam has a brother that has cerebral palsy and his bedroom is right next door down the hall. We were sitting there playing this Air combat fighting game, we were all taking turns playing the game, then his bedroom door came open, it was his cat named lilly, she hopped on the bed. I petted her for a few seconds, she got down and left the room.
We continued to play our game, then all of the sudden we hear a faint noise that was louder than our game, I turned to adam and said "did you hear that" adam replied "I think I heard something", his girlfriend was sitting there in disbelief, she said "I heard it". I turned the game off and everything got quiet, we sat there for a few moments then out of no where, we heard this beautiful music coming from a piano, we all looked at each other, I said "adam is your brother home?", he said "he don't get home until after 6", I looked down, he had a bat sitting beside his bedroom door, I grabbed it and clenched onto it, he grabbed a sword off his wall, we proceeded out his bedroom, we looked down the hall, it was coming from his brother's bedroom, we looked at each other, then looked down the hall.
The door was slightly cracked, we got to the door, the music stopped, it was pitch black in his brother's room, Adam says "nathen are you in there" no one replied. Adam got a concerned look on his face, he raised his foot and kicked the door open quickly, flipped the light on... No one was there. Now his cat was sitting on the little stool at the keyboard player, she looked up at us and meowed. Now we were hearing something like mozart or some thing, I looked, the thing was turned off and it was unplugged, so until this day we still don't know what was going on, it was freaky.
You may want to find out the home's history to see if anyone passed away there like one of the previous owner or owners.
It is not uncommon to hear piano music that is residual, happening in our current present day, but is coming from the past as a past energy imprint.
Yet, in the case of your story, it sounds like the music was coming from the present day, electrical piano and played by an unknown being without it being plugged into an electrical outlet. I cannot say that this does not occur, but it does take a quite a bit of energy for ghosts, or spirits to manifest in our 3D physical world. The being would have to go out of its way to play the piano and there was not even an electrical outlet to draw energy off of it to manifest. I am not saying this is impossible, but I have researched such things, and many times the manual pianos are used, as they are most likely easier to manifest the music from and to have it come from a bygone time in the past as a residual haunting.
It could be possible that there could be a present day residual haunting where the music you heard was previously played on that current day, electrical piano and the residual was left in the room as a piano music, energy imprint.
Well, only you can decide what happened as you experienced it. I can only speak from my own personal experience and many of the things I have heard in haunted houses or places related to piano music have been residual in energy imprints. Otherwise, if I have heard a note or some music in present time, the piano has been manual or non-electrical. When I have experienced things from electrical objects they have been plugged in such as TV's, radios, etc. Switching on by themselves and voices or music coming across between the broadcasts, as well as all types of recorded tapes (cassette, VCR, phone, etc.) recording EVP's.
I am open to others who report such occurrences and am not closed to another's sharing of such an experience. I just have yet to experience this experience you speak of within your story.
Thus, as always, it is up to you to decide what you experienced. Certainly, I do not expect others to always or fully believe my experiences either. No matter what the other guy or gal may think, I can only tell my own truth, because I am the one who has to live with it and live in it. :)
Appreciate your story,--Abby