For reasons of experimental design, most work on music and memory necessarily focuses on subjects' ability to recognize and accurately reproduce music they've been exposed to in the laboratory. Still, some more general observations about how memory works can be brought to bear. Professor Michelle Miller is a cognitive neuropsychologist, specializing in speech and language processing, who has taught at UCLA, Rice, and Northern Arizona University. Long-term memory is best described as a vast interconnected network, but you don't get to determine all the connections. When you feel like you're voluntarily pulling a memory up, you're tracing a link back from what you're thinking about now to something else.
Voluntary control is just a small part of remembering anything.
So even though our memories may be structured like a network, this structure doesn't seem to be realized in the brain in the straightforward way one might expect. Additionally, Miller says, having a song running through your head, even when you're not making any sound, is more like singing than listening. Imagining something, for the brain, is almost the same as really doing. All you subtract out are some low-level processes, in this case, the coordination of motion and breath. Just about anything, to hear Miller tell it.