Per 
Item #: SCP-9001
Object Class: Pending
Containment Procedures: Sheet music is to adorn the walls of SCP-9001's containment cell. Further experimentation is to be proceeded with caution; if done, any and all request made by SCP-9001 must be taken with absolute security and authority, and a team of EMT Specialists must be present at all times.
Description: SCP-9001, henceforth referred to as the "Pianist", is a bearded man who appears somewhere between the ages of 80 and 100. The entity is enrobed in thick garments, which change hue upon the arrival of a person. The Pianist is consistently in a state of hyper paranoia, yet is docile and rarely shows signs of aggression. Furthermore, it is routinely engaged with a piano, which appears out of constructed matter at the will of the entity. To be noted: any photographs taken of the entity will turn white; all but one visible recreation exists of it.1
As shown in test T-9001-1, upon the Pianist striking a key on a fabricated piano, a page of sheet music will gravitate towards the entity. It will slowly rise above the piano, before violently erupting to create a portal of the same dimensions of the sheet music. Beyond this portal, a tower can vaguely be made out of the horizon; the portal will remain until the Pianist rises from the bench of the piano. Given enough complexity of the notes, a substantial number of portals will open, at which point they will merge and the Pianist and any onlookers will be transported to the tower.
As documented by D-REDACTED, the tower is made of an Earth-like stone. The following is the encounter between D-REDACTED and SCP-9001, logged as T-9001-1:
The Pianist: What do you desire, mortal?
D-REDACTED: Erm… I was assigned to document you.
The Pianist: Interesting. And with what will you use to accomplish that?
D-REDACTED: I guess my dignity; whatever I have left of it, anyway.
The Pianist: Hmm… You do not appear keen to this moment. Perhaps I can indulge your fantasy?
[Note 1:It appears that, at this moment in the encounter, D-REDACTED is put under a trance from the Pianist. Immediately following this, the Pianist fabricates a piano into the cell and begins playing it. As this happens, audio and visual communications to the cell are cut off, and D-REDACTED is transported to the tower, along with the Pianist. The remaining encounter is documented through the device equipped by D-REDACTED.]
D-REDACTED: What is this? Where am I?
The Pianist: Hush, you must not speak in this place!
D-REDACTED: I deserve to know what kind of shit you pull, man. Where are we?!
[Note 2: The following image was documented by D-REDACTED. It was uploaded to receiver HGL2G:]
[Note 3: The visual component of the device carried by D-REDACTED failed after this photograph was taken. The remainder of the encounter was documented by the failing audial component and was transcribed. It was received by GGTR-S.]
Reading One:
Voice One: N- WHY IS IT LIKE THA-
Voice Two: ENTH- THE GLORY OF M- SHE RI-
Voice One: RECALL. RECALL. RECALL. RE-
[Note 4: End encounter T-9001-1.]
T-9001-1 Aftermath: Immediately after the test, the Pianist returned to the cell alone. It appears that, under unknown circumstances, D-REDACTED died while in what will be referred to as the "Tower Realm." It should also be clarified that the sheet music stayed floating during the visit to the Tower Realm, but it showed the reflection of the measuring device instead of a distant tower.
The Pianist seemed content after the visit, and it seems that the following two tests proved the same: whenever a person is brought into the Tower Realm, the absence of them delights the Pianist. It is currently assumed that the Pianist murders them, though the means by which it is done are unknown.