MU 207 Midterm Study Guide

Office hours 4:30 - 5:30 pm Tues

MacLaurin A177

Source
materials: CLASS NOTES, TEXT,
VIDEOS

Introduction
to acoustics. Sinusoids, Hooke's law, SHM

Vibrating
spring vs. vibrating string, *v* of a wave on a string:

(*T* = tension in Newtons, µ = mass per unit length)

Amplitude, frequency, period, phase

wavelength: v =
f λ

T = 1/*f *or *f *= 1/T (T is the period)

Harmonics,
resonance, standing waves, difference between modes and nodes

Fourier
Theory, *Time domain *vs*. frequency domain*

Digital
Audio, Sampling, Information theory: Nyquist/Shannon

Sampling
rate, aliasing

Quantization,
dynamic range ("6 dB per bit"), mp3, perceptual coding vs lossless compression

How
does a computer make music?

The
physics and mathematics of intervals, cents, tuning systems: just, Pythagorean, meantone, equal tempered

*pythagorean* and *syntonic* *commas*

**Psychoacoustics****
: **anatomy of auditory system, tonotopicity,

Fletcher-Munson curves

ANIMATION: Auditory Transduction

__The Science of Musical Scound__ (coursepack):

Chapter 3 is about sine waves, harmonics, harmonic series (p 44), resonant modes (standing waves) and **Fourier Theory**.

Chapter 4 is about tuning systems, and has a slightly different take than the way I presented it, but this chapter describes just intonation

**Just intonation** is specifically derived in **Figure 4-5** on page 70, **cents **on page 72.

Chapter 5, pages 78-82 are about **critical bands**

Chapter 6, page 92-95 is about **virtual pitch** (Jan Schouten)

Chapter 7 is about the anatomy of the auditory system, p 112 discusses **critical bands** again briefly.

Chapter 8,
page 123 describes **Fletcher-Munson** *equal-loudness curves*

**Not
on midterm:**

MIDI and computer music systems. (Appendix G)

Musique
Concrete, Early Electronic Music

Reference (not necessarily all used or referred to)

• At room temperature (68° Fahrenheit), the velocity of sound in **air **is: 343 meters/second = 769 mph = 1,128 feet/second = 769 miles/hour.

In **water ** the speed of sound is: 1,497 meters/second.

where *v* is velocity, L is length of the string or air column

*where v* = velocity of a disturbance passing along a string,* T *is tension of the string, µ is mass per unit length (thickness)

(if your calculator can't do log base 2)

"6 dB per bit"

1¢ is defined as** 1/100th of an equal-tempered semitone**

* Quarter-comma Meantone temperament:*

C D-½δ E-δ F+¼δ G-¼δ A-¾δ B-δ C