Hi BoogieBunny and Welcome to HealingWell,
Im really glad that you have found us and that you feel right at home. Its amazing to realise that there are people out there who feel the same way that you do... its such a good feeling to know you are not on your own. I have heard of music being a trigger for people before but it has always been as background music. Is it a particular style or a particular artist that triggers you? I cant imagine a life without music... it would drive me insane.
I am wondering if your trigger is something to do with acoustic memory. It seems strange that its only known songs which are a trigger (Suggesting memory) but I am assuming you dont have issues with other kinds of memory recall which suggests its an acoustic-specific area. This could either be within the temporal lobe (where language is predominantly processed) or possibly in a region of the frontal lobe where memory predominantly is. There are loads of bits in between but that is what I am thinking mainly. Its not something that I have come across before so I am kinna thinking on my feet a bit here!