The pitch wheel can be found on most modern synthesizers and MIDI keyboard controllers. The wheel is designed so only half of it is raised from the interface. The main use for this wheel is to create smooth pitch bends or to raise/lower the pitch of notes you are playing.
The pitch wheel uses MIDI messages as it is moved up and down and is interpreted by the receiver to alter the pitch. You will find that most pitch wheels are spring-loaded, so that whenever you move the wheel it will always revert back to the middle position when you let go.
On the surface, pitch bend wheels can look quite basic but used correctly you can achieve some exciting and professional sounding effects. You have three different aspects of using the pitch wheel, each one will give you varying amounts of effects and results.
The first one is the direction of the wheel, move it up to increase the pitch and down to decrease the pitch. The second aspect is distance and this describes how far the pitch is bent. Lastly, you have the duration which describes the amount of time it takes to reach the intended destination.
You are able to control the range of pitch bend on most synthesizers, the standard range is 2 semi-tones up and down. 2 semi-tones gives you a range of one whole tone and is the best setup for beginners. Setups can vary with increased ranges for more advanced pitch bending.