I think there's a profound difference in the aural vs. visual experience. For me, imaginging songs, "hearing" an earworm, even for songs in other languages, I think I'm using my inner monolouge system. Instead of thinking, I'm "inner humming". The profound difference being, we can produce sounds, we can sing, hum, go "ba-doom-tish!" in our heads. But we can't (at least I can't) produce visions at will. I must be able to in some sense because I remember things I "saw" in dreams. And I can get a sense of places I know - usually the best remembered are from my childhood. Things that I've remembered a hundred times. But if you ask me to imagine an apple, there's nothing to be seen even though I can think of its shape, and details and draw what I'm thinking of, which is basically a memory of an apple. However, at night, with eyes closed when drifting off to sleep, if I think about what my closed eyes are "seeing" I can get very vague impressions of random things. On occasion I've been able to influence what pops in there to an extent but I can't do it on command. What I think is happening here is there's enough noise in my visual processing that lines up to remind me of something - a house, a tree and my brain fillsin the rest. But even this is like a looking at a photographic negative with candlelight that goes out after 250 ms.