Per 
Special Containment Procedures: SCP-4XXX is to be stored in a residential-style safe at Site-23 Site-98. The safe is to be secured with a combination lock, the code to which is to be known only to Level-4 personnel or higher. The safe is to specially fitted with a heating system, and is to be heated to 37°C. Under no circumstances should it leave the range of 36.5°C to 37.5°C. Local atmospheric pressure appears to have no discernible effect on SCP-4XXX. SCP-4XXX appears to be entirely non-sentient and non-biotic, and does not attempt to breach containment, nor has it the will to do so. Instances of SCP-4XXX-2 have the ability to breach containment, but do not appear to express the will to do so.
SCP-4XXX prior to being placed into containment
Description: SCP-4XXX is a manual, mechanical cylindrical music box which - when its handle is turned by a human operator - plays a 30-second rendition of Russian romantic composer Pyotr Ilyich Tchaikovsky's Swan Lake. The subject affected by SCP-4XXX is known as SCP-4XXX-1, and all instances of SCP-4XXX-1 fully subjected to SCP-4XXX's anomalous properties are known as SCP-4XXX-2. Note that its anomalous properties do not manifest in instances of SCP-4XXX-1 which are not Homo sapiens. Neither non-human biotic instances nor non-biotic instances experience SCP-4XXX's anomalous properties. Whether SCP-4XXX's properties manifest in humanoid SCPs is yet to be established.
One of SCP-4XXX's main anomalous properties is its ability to exert an influence on the surrounding area when it deviates from its desired temperature. When kept within the range of 36.5°C to 37.5°C, SCP-4XXX's effects manifest only in SCP-4XXX-1 which operate SCP-4XXX. However, as the temperature deviates from this range, a 'sphere of influence' grows outwards from SCP-4XXX. This sphere of influence is known as SCP-4XXX-3. The volume of SCP-4XXX-3 is proportional to the deviation of SCP-4XXX from the range of 36.5°C to 37.5°C. This proportionality may be described as
(1)where r is the radius of SCP-4XXX-3 in metres and T is the deviation of SCP-4XXX from the range of 36.5°C to 37.5°C. Any instances of SCP-4XXX-1 within SCP-4XXX.3 undergo the stages described below, in accordance with the SCP-4XXX's automatic operation.
Interestingly, if SCP-4XXX is at its optimum temperature, an SCP-4XXX-1 listening to the song produced does not experience the effects of SCP-4XXX's anomalous properties, SCP-4XXX-1 only experiences the effects if they manually operate SCP-4XXX. The same is true for when SCP-4XXX-3 is generated; only SCP-4XXX-1 that are within SCP-4XXX-3 are affected, they are not affected by simply listening to the song.
SCP-4XXX's other main anomalous properties manifest when operated by an instance of SCP-4XXX-1. There are several discernible stages of effects, concluding after 3 full playings of SCP-4XXX's rendition. Stage-1 occurs after 1 playing of SCP-4XXX's rendition. SCP-4XXX-1 will begin to speak with a heavy accent, applicable to a Russian native who speaks English as a second language. Subsequent stages are continued per each subsequent playing of SCP-4XXX. In Stage-2, SCP-4XXX-1 will experience heightened musical creativity, expressing a desire to play any number of classical instruments - Note that SCP-4XXX-1 will be masterful at playing any given instruments, notwithstanding any previous experience with the instrument played. In Stage-3, SCP-4XXX-1's body will begin to morph into a full biological replica of SCP-4XXX-2, over the course of the 30 seconds of playing. This process appears to be extremely painful. Note that the reproductive organs appear to be entirely unaffected by this process, with female instances of SCP-4XXX-1 maintaining their female reproductive organs. The mammary glands in female instances of SCP-4XXX-1, however, are affected.
SCP-4XXX-2 are replicae of composer Pyotr Ilyich Tchaikovsky. Instances of SCP-4XXX-1 that become SCP-4XXX-2 speak fluent Russian and no English, and have a desire to compose and play music reflective of Tchaikovsky's classical romantic style. Note that Class-D personnel who are transformed into instances of SCP-4XXX-2 are to be terminated after all wanted experimentation is complete.
NOTICE FROM THE FOUNDATION ETHICS COMMITTEE
Following Experiment-4XXX.RF, under NO CIRCUMSTANCES is authorization for experimentation of Class-D personnel with item 4XXX to be granted.
— Ethics Committee
Addendum 4XXX.1: SCP-4XXX was discovered on 23/12/201█ in Pierce County, ██. Foundation staff were notified after numerous 911 calls were received from frantic locals, who claimed to have seen several replicae of Pyotr Ilyich Tchaikovsky conversing with each other and roaming the town. SCP-4XXX was found in the house of Mr. ███, who had been converted into an instance of SCP-4XXX-2. The local temperature was at around 15°C and dropping into the night, which had rendered SCP-4XXX-3 to be 1061.208m3 - per and had already created multiple instances of SCP-4XXX-2. Instances of SCP-4XXX-2 already present in the area numbered at █. While initially considered harmless, several instances began to ███████ before being terminated by Task Force Beta-7.
