Feedback Outline:

Feedback is related to resonance. It is a buildup of energy, a small amount of energy reinforces what is there and it builds up

I. Our first demonstration uses the light interferometer. Feed back is acoustical, reinforced through vibrations. (An interferometer is used in rap and hip hop… fact or fiction?)

II. The second source of feedback is the microphone. It is usually an unwanted beast. A microphone hearing itself, builds up a loop. The acoustics and amplifier settings will determine the pitch of the feedback. It can be controlled both physically and electronically.

III. The third demonstration is the guitar feedback. . A guitar string vibrates to the sound it is hearing that is amplified which makes the string vibrate more and so on. Again the pitch can be controlled physically and electronically.

History of Guitar Feedback.

§ First ones to use feedback? The Monks

§ The Monk chant: http://www.youtube.com/watch?v=-5iI0__9S1c

§ First Recorded Feedback? The Beatles…I Feel Fine…

§ http://www.youtube.com/watch?v=kge_Krzuegs

§ Actual Live:….

§ http://www.youtube.com/watch?v=-sVi9qNJOaM

§ The Master of Feedback http://www.youtube.com/watch?v=zXkeFmQ52Yg

§ Rainbow Bridge version http://www.youtube.com/watch?v=pPTP_JyQpl8

IV. Electronic Oscillators Feedback causes an electrical oscillation. A controlled oscillator is called a signal generator, Pitch is controlled by changing the value of an electronic component usually a capacitor.

V. Controlling the Oscillator…Exterior capacitance… The Theremin.

§ Beach Boys Good Vibrations

§ http://www.youtube.com/watch?v=CelV7EbuV-A

§ Led Zepplin Whole Lotta Love Live Jimmy Page Used one. Checkout the movie The Song Remains the Same

§ http://www.youtube.com/watch?v=Tdmh-3AovE0