From Scp Wiki
Object Class: Euclid
Special Containment Procedures: Item SCP-020 is located in Non-Critical Storage Unit 5, where it remains under video observation. Personnel entering the room are only advised not to touch SCP-020 or any apparition seen playing it.
Description: SCP-020 was discovered in the Russian ghost town of Promyshlennyi. SCP-020's appearance is always that of a stringed keyboard instrument, but every aspect of it besides that changes constantly. Its most frequent embodiment is a black grand piano, which it assumes approximately 30% of the time. Its variations seem unlimited in time period or decoration, and it has been observed as a spinet, an upright, a player piano, a clavichord, a harpsichord, a virginal, and many others. Research as to why or how the object's alterations occur has not produced any definite conclusions.
On some occasions, vague human apparitions have been observed playing SCP-020. The apparitions' dress and choice of music almost always correspond to the instrument's ornateness and period of origin. The most notable appearance during the item's presence at Site 19 was late performer Glenn Gould, who was rehearsing two Bach Inventions on SCP-020 for approximately seven minutes during 1997.