I believe Tolstoy was talking speaking, in part, about the writers of songs, of poems, and of books.
“This is a place of mystery, Daniel, a sanctuary. Every book, every volume you see here, has a soul. The soul of the person who wrote it and of those who read it and lived and dreamed with it. Every time a book changes hands, every time someone runs his eyes down its pages, its spirit grows and strengthens. This place was already ancient when my father brought me here for the first time, many years ago.”