Monk Mercuriy's evidence.
A similar evidence, relating to the same years, is found in a diary of a Caucasian anchorite monk Mercuriy, who speaks of himself in the third person as 'the beekeeper':
"One night the strange occurrence repeated during his reading the midnight prayers. The music was playing deep inside his mind, perceived by the inner ear, and now it was a whole symphony orchestra. Violins, cellos and the double-bass were clearly heard, though he could not say what exactly was on. It was a long-drawn piece of music of two-and-a-half-hours length, impossible to stop or distract from and terribly interfering with prayer. The hermit had to go on listening to the unbidden concert giving up his regular canon. As soon as he gave up his attempts to pray and went to bed it stopped.
Next page night when he was just going to start the Mesonycticon he heard another concert. This time it was a brass band. To the accompaniment of the triumphant blare troops seemed to be marching past his lonely cell. Carried away by the catching tune, he did not even notice how he started to beat the rhythm with his right hand. So that night also was lost. The devil skilfully prevented the beekeeper from prayer. There followed a whole series of such concerts, now vocal, now instrumental, almost every night. Once even at daytime he heard somewhere very near behind the cell the town cathedral choir singing, and could well discern its main chorister's familiar soprano.
One midnight concert was really remarkable. It was apparently the demon's own composition performed on some metallic instruments producing incomprehensible and amazingly tender sounds that bore a remote resemblance of the pleasant vibrating striking of an old clock. The melody was very much alike the old Italian waltz 'Neapolitan Nights'. The beekeeper first remembered the tune, yet by dawn all had vanished from his memory" (Monk Mercuriy. "High in the Caucasus", Moscow, 'Palomnik', p. 1998).
Among Russian composers the most obvious medium was A.N. Skriabin (1872-1915), who considered himself a great 'missionary', a prophet and even the Antichrist. His anti-Christian, satanic trend is deliberately stressed in his opuses' very titles: 'Poeme satanique', 'The Black Mass' (the composer's title for his Ninth sonata).