Physics Behind Music An Introduction

Various sound-recording technologies are presented that use different mediums and different encoding methods for the recorded signal. Analog and digital are two broad categories used for encoding. Sound signals can be recorded using a physical change to a material, as is used for vinyl records and some CDs and DVDs. Signals can also be recorded using magnetic materials and their interaction with electromagnets. Optically encoded signals involve a change in the reflection or transmission of light from a material, including the analog signals used in older movie films and digitally recorded signals for newer recordings. Two examples of digital recording encoding are 1-bit and base-2 binary. Nyquist folding, used when sampling is too slow, is introduced.