While we were in Williamsburg, VA on vacation, we took in a concert by Dean Shostak, master of the crystal instruments. He played something called a "Glass Armonica", first invented by Ben Franklin and composed for by Mozart in the mid-18th Century. It was lost for years, and only rediscovered as viable musical instrument in the early 1980's.
He also demonstrated a beautiful glass violin:
As well as a set of glass handbells: