Woody asked Bill Medley when he changed his last name to "Righteous". Medley and Bobby Hatfield were known as The Righteous Brothers, but they were not related. They got their name because "righteous" was a popular slang term among African-Americans for "cool", and when they sang R&B at clubs that drew mostly black customers, after they did a few numbers those customers would say, "You guys are some righteous brothers". The name stuck.
This episode was followed by the 8th Anniversary Special (1990). of Late Night With David Letterman. The cold opening featured the "Cheers" cast surfing for something to watch on TV. When the remote broke the TV was stuck on the Letterman special - which emptied the bar.
Rebecca replaces the beer nuts with heart-shaped candies with messages on them. Sweethearts (also known as conversation hearts) are made by the New England Confectionery Co., also known as NECCO.