Conversation so far:
Is Jascha is a good violin player?
Heifetz was "regarded as the greatest violin virtuoso since Paganini,.
What was some of his famous songs?
CANNOTANSWER.
Are there any other interesting aspects about this article?
Heifetz was very particular about his choice of strings.

Question: What were his choices?
Self-contained rewrite: What were Jascha Heifetz's choices?