The Whammy bar is a rod-shaped appendage attached to the Guitar Hero Controller. It has many names including, vibrato bar, tremolo bar, wobbly stick, or even wang bar!
Importance in Guitar Hero
The whammy bar can only be used on sustains(long notes). When wiggled back and forth the player can change the pitch of the held note. Through experimentation and repeated use, one can come up with cool or even comical new sounds to use in a song.
Whammying on sustains of any kind does not affect the amount of points you get on said sustains. Outside of changing the way notes sound, the only use the whammy bar has is to to aquire Star Power. When a Star Power Path contains a held note, the player can use the whammy bar to fill up their Star Power Meter. The speed the player moves the whammy bar does NOT affect how much and how fast the meter fills up; the meter fills up at a set speed when whammying.
If the player is using a standard game controller, the whammy bar becomes the left analog stick, (PlayStation 2, PlayStation 3, & Xbox 360) or is activated by shaking the controller (Nintendo Wii).