2 things come to mind -
I have an excellent visual memory that gives the most when driving through cities or places I've never been to (one drive through is enough for me to remember where I need to go next time I find myself there)
I have a huge library of songs that are ingrained in my head, built since early childhood. I don't really need a music player although I do use one when I use the public transport. I don't know about others (maybe everyone can do that, I never really asked) but I can play my chosen song in my head and listen to it in its entirety or just specific parts of the song, I can play it in a loop or play specific parts in a loop etc.etc. I can hear the whole composition but I can also focus at will on particular instruments and dampen the others, so I can sorta mix too lol.