I can hear music in my head before I go to sleep. What does this mean?

[Space_guinea_pig1347]

I have a very unique......talent? I do not know what to call it. I can hear music. What I mean by that is that when obviously no music is playing, I can manually"turn music on " in my head. It is so weird because I can hear anything I want if I concentrate. It has to be completely quiet. And the sound is very clear, like headphones. I don't even have to know the words! I am  teenager but I have had this since I was about six. Among the songs I've heard are "let her go" by passenger, "cross my heart" by Maroon 5 and "radioactive" . I wish I knew what this was and if anybody knows what it is can you tell me?