This segment of Eva Cassidy aired way back in May 2001.  Per Wikipedia, “The Nightline episode has since been rebroadcast three times due to popular demand. Producer Leroy Sievers has said that it is “probably the most popular Nightline ever“.

She was like one of those great painters whose work wasn’t appreciated until after their death, never knowing how much their art and talent, and themselves, would be loved.

https://www.youtube.com/watch?v=bXU219b3Zdw