The sound of the piano doesn't just add to a restaurant's romantic atmosphere. According to recent research, it also changes the flavors of the entrees. In 2011, researchers at Oxford University showed that participants given a piece of cinder toffee -- a treat chosen for its sweet and bitter flavors -- judged it as tasting sweeter when they heard a soundtrack that was electronically altered to include more high-pitched, piano-like tones. Likewise, participants rated the toffee as more bitter when the same music included more low and brassy notes. This could have big implications for wineries, restaurants, and anywhere else where flavor is the focus.