Bonnie Bramlett.

Did you watch Rosanne as a kid? Since it was the number one or two rated show for its first few seasons, chances are good that you did. And if you were raised in a family of seven kids in the 80s and 90s, "near" the fictional town of Landford, IL, chances were real good. 

To this day, I still remember this scene at the end of an episode, for being very poignant and one of the first glimpses into the world of music and the blues. I feel Bonnie Bramlett doesn't amazing job with the song and conveying the end of the episodes' story line. 

http://youtu.be/1y4ptVHmEIs

If you've never seen it, watch it now.