A melodic mystery has been solved in Southern California.
A piano perched on a mountain in Santa Monica sparked a chorus of social media photos from baffled hikers because the sound seemed to appear out of nowhere.
It turned out that a group of friends took the piano and trekked up the mountain in harmony for a music video shoot.
Filmmaker Michael Faner and his friends finally reached the Topanga Lookout, one mile and one hour later.
It is still unknown if the piano will be taken down off the mountain.