Conversation so far:
Waht did Fred Frith do in New York?
Towards the end of 1979, Fred Frith relocated to New York City, where he immediately hooked up with the local avant-garde/downtown music scene.
What did Fred Frith do with the local avant-garde/downtown music scene in New York?
Fred Frith met and began recording with a number of musicians. He spent some 14 years in New York, during which time he joined and started a few bands.
Why was the New York avant-garde/downtown music scene liberating for Fred Frith?
For the first time Fred Frith felt that he could be himself and not try to live up to what he imagined people were thinking about him.

Question: How did this change him?
Self-contained rewrite: How did the New York avant-garde/downtown music scene change Fred Frith?