When I was in middle school, I had a friend I was very fond of. The two of us (and a handful more people) formed a very close group with strong bonds. Most of all, what united us was probably our common aversion to things such as loud music and "traditional party culture". This led us to have our own parties, usually very tame. We had a lot of fun and this became sort of a tradition.
When high school came, this friend went to the dark side. She became popular in her new school and now throws the craziest parties, with the loudest music, insane amounts of booze and loads of new friends who love "partying hard". Me (and all the other friends from the old group) haven't changed and we absolutely hate those parties. We are usually left uncomfortable in a corner, trying to talk.
How can I avoid this friend's parties without offending her and also make it clear that I still like her and care for her?