answer:I don’t listen to much music anymore (I’m old). I prefer to play music (guitar, piano, etc), but I have very little time for that. I do, however, often have music playing in my head. It isn’t necessarily a song that I have heard. It is usually something that builds slowly and may be influenced (as all art/music is) by existing songs, but often will morph into something completely different. When I do listen to music, I will always have things in my mind that I use to alter the piece. For example, I may imagine a second guitar or additional percussion. There may be a harmony part or strings where there are none. I’ve always done this, and I prefer my “version” of the song to the one recorded by the artist. A few years ago I admitted that I have always done this and many of my friends and family found it quite odd. Anyway, I have never left a song unaltered in my head. Note: I also pay little attention to the lyrics. I have no use for them. I was allowed to play in the band when I was a kid (trombone), and later saved up my allowance for a keyboard. Then, the guitar. My parents didn’t necessarily encourage it, but they were supportive. Could I live without it? External sources? Sure. Internally? Nope.