A Brief Introduction to the Physics of Music

I wrote these notes a while back while studying instrument physics and music theory as a part of my training as a composer. They are broken into three main sections: intonation, which discusses tuning instruments and our modern 12-tone chromatic scale; harmonics, which discusses some detail of how exactly musical instruments produce the sounds they do; and timbre, which discusses why different instruments have different tone quality. I am not a physicist, so if you find any errors, let me know at drew@drewpendergrass.com.

I encourage you to download Audacity, an excellent and free audio recording and editing program, before you start this tutorial.

• 1. Intonation
• 1.1. Beats and Sound Waves
• 1.1.1. Brief Introduction to Sound Waves
• 1.1.2. How a Microphone Works
• 1.1.3. Measuring Sound
• 1.1.4. Beats
• 1.2. Scales
• 1.2.1. Pythagoras, the Pythagorean Scale, and the Circle of Fifths
• 1.2.2. The Just Scale
• 1.2.3. Equal Temperament
• 1.3. Tuning Your Ensemble
• 1.3.1. Adjsuting Your Instrument
• 1.3.2. Adjusting to the Ensemble
• 2. Harmonics
• 2.1. The Overtone Series
• 2.1.1. Building a New Level of Sound
• 2.1.2. Harmonics vs. Overtones
• 2.2. Timbre 101
• 2.2.1. The Relationship Between Overtones and Timbre
• 2.2.2. Using Computers to Fake Timbre
• 2.2.3. How Does It All Happen?
• 3. Timbre
• 3.1. Timbre of Stringed Instruments
• 3.1.1. Standing Waves
• 3.1.2. The Physical Nature of Overtones
• 3.1.3. A Little Bit of Math
• 3.1.4. Acoustic Amplification
• 3.2. Timbre of Wind Instruments
• 3.2.1. Methods of Vibration
• 3.2.2. Modes of Vibration
• 3.2.3. Changing Pitch
• 3.3. Timbre of Idiophones
• 3.3.1. Idiophones
• 3.3.2. Membranophones

Unless otherwise noted, all images are created by myself and can be reused by anyone under a Creative Commons Attribution 4.0 International license. The same goes for the text of the notes themselves.