Transfer files

Trying to transfer some music files from my pc to my android phone and having a problem. I read up on how to do this function, but I hit a snag when I click on the MTP box that comes up on my phone. It is checked and I thumb it, but i do not see anything on my pc screen which is suppose to give me options on how or what I want transferred. What am i missing here?

Hi, yeah, i d/l that app you recommended and found out later that it is not a free app. I am not looking to pay a monthly charge just to transfer a few favorite music files. ..that I most likely would use only once. Whatever happened to the old fashion free way. I recall a few years ago on a cheaper android phone i was able to transfer those same music files by merely connected the usb cable to my pc...But for some reason I cannot find a way to do that now.