80's Sitcom - Cosby Show - Best Singing Scene

The Cosby Show was the highest rated TV sitcom in the 80's.  I loved the show and used to watch it every Thursday with Cheers following right after.  Here is one of my favorite moments from the show.

Flashbacks:

-Cliff Huxtable's parents
-All 5 ladies dancing.  Most guys had a crush on Denise.  I liked Vanessa :)
-Theo Huxtable.  I met him randomly in Hollywood last year and he looks exactly the same!
-Rudy Huxtable.  She's absolutely adorable.

Bonus Question:  Can you name the singer of the song?

Answer: Ray Charles singing "The Night Time is the Right Time"