Shania- because I've literally listened to her for my whole life. I love almost all of her songs, and she has the talent and legacy to back it all up.
Taylor- I've loved her from the very first song. There are very few songs she's written that I don't like. I'd stan for her no matter what.... she just coincidentally happens to be incredibly successful
Gaga- I didn't really start listening to pop music until 2009, and I didn't really like Gaga until the 2009 VMA performance when I realized "hey! there was an intelligent person on stage singing!" That was really got me into her; the fact that everything had a meaning... I'm starting to drift away from that though
