Slang: Getting a reach around while having your vocal cords played by a cock.
Original Definition: a lever attached by the bridge or tailpiece of an electric guitar that can be depressed to increase the tension of the strings and produce such effects as vibrato, portamento, and dive bomb.
Their voice was really hoarse after getting that Whammy Bar!
Your voice is really raspy, are you sick or did you get Whammy Barâd?