# chapters 4 and 5 of on repeat **Opening (not a real abstract):** Few people are spared the at least occasional experience of being gripped by the obstinate unfolding of an imagined line of music. Although the sound might not exist at the present moment in the real world, or be audible to anyone else, it can seem compellingly, maddeningly real. An episode of this sort often seems more like the reliving of a tune than the simple remembering of it. If I remember hearing a concert performance of Brahms’s Second Symphony, the memory might include something about the hall, the view from my seat, how many movements there were, the perfume of someone in the row behind me, a bit of lush orchestral timbre, and the expressive resonance of the piece. These recollections emerge jumbled together, without a clear temporal order that I could relate, let alone the temporal ordering in which they originally occurred; and they emerge in a flash,