Episode 222. "Mom and Pop Art"
Guests: Jasper Johns (Voice of Himself) Isabella Rossellini (Voice of Astrid Weller)
"Homer reluctantly agrees to do some yard work, but his trip to home improvement store results him buying a do-it-yourself barbecue pit. His feeble attempt results in something that an art enthusiast considers "outsider art." When Burns pays big bucks for Homer's piece, he decides he is an artist. However, fame is fleeting because his art has become repetitive. So he concocts an idea that simply floods Springfield with good feelings about art."
b: 11-Apr-99 pc: AABF15 w: Al Jean d: Steven Dean Moore
http://www.tv.com/the-simpsons/mom-and-pop-art/episode/1507/summary.html
Video of the episode: MP4 version -- password protected.