yaa i knw abt chord families. And that was not a chord progression , i know G A are not in the family of Dm But they often come and fit so correctly. Y dis wat is the theoritical explaintion for it, der mst be some relation for dis to happen. I hav been in theory much later n not been to any guitar class. My frnd taught me few basics and major minor chord, its now only that i hav been into theory so it is sometimes confusing and i really dont get it y i m learning all the scales modes and so many things frm the books dat i hav, bcoz ealier also i was able to find the notes and chord pretty correctly widout knowing much of theory with my own fundas and now also the same. I need to improve myself.