Science and Music

James Jeans

• Publisher: Rare Treasure Editions
• Year: 2021
• ISBN:
  9781774644102
• Topic: Media & Performing Arts
• Subtopic: Ethnomusicology

As the author mentions in the Preface, the intent of the book is to explain in a non-technical manner the main outlines of parts of science specially related to the questions and problems of music, assuming no previous knowledge either of science or of mathematics on the part of the reader.Sir James Jeans, who was a noted British scientist, gave a physical analysis of musical sounds, in what is considered to be the best exposition on the subject, a book of great intellectual stature. His aim was to convey precise information, in a simple non-technical way, that will be of interest to the amateur as well as the serious student of music.The discussion begins with an explanation of the development of the human faculty of hearing. For example, why do some sounds produce pleasure when they reach our ears and some pain? How do we retain the pleasurable quality, as it passes on from one stage of electronic equipment to another? These and other pertinent questions on the transmission and reproduction of sound are answered. The various methods of producing sound, and the qualities of the sounds produced, are further discussed as they relate to vibrations of strings and harmonics, and vibrations of air. Harmony and discord are also considered. In the final chapters on the concert room and hearing, the discussion focuses on the transmission of sound from its source to the eardrum and from the eardrum to the brain. A general theory of acoustics is also covered as well as acoustical analyses."Science and Music is a rare book, as an author does not often combine very distinguished scientific abilities with musical knowledge and power of simple exposition. It will probably become a minor classic." - Manchester Guardian.

Science and Music

by Sir JAMES JEANS

O.M., M.A., D.Sc., Sc.D.,
D.L., LL.D., F.R.S.

PREFACE

Much has been added to our scientific knowledge of musical sound, since Helmholtz published his great work Tonempfindungen in 1862. The new knowledge has been often and well described, but mostly by scientists writing for scientists in the technical language of science.

In the present book I have tried to describe the main outlines of such parts of science, both old and new, as are specially related to the questions and problems of music, assuming no previous knowledge either of science or of mathematics on the part of the reader. My aim has been to convey precise information in a simple non-technical way, and I hope the subject-matter I have selected may interest the amateur, as well as the serious student, of music.

I need hardly say that I am indebted to many friends and books. A considerable fraction of my book is merely Helmholtz modernised and rewritten in simple language. Another considerable fraction is drawn from the wealth of material provided in the notes added to Helmholtz's book by his English translator, A. J. Ellis. On the less technical side, I have borrowed largely from Dayton C. Miller's book The Science of Musical Sounds (The Macmillan Company, 1934), and am especially indebted to the author for permission to reproduce eleven excellent photographs of sound-curves. Among other sources from which I have[Pg x] drawn largely, and found especially valuable, I ought to mention:

Sound by Lord Rayleigh (2 vols. Macmillan & Co.);

Sound by F. R. Watson (John Wiley, 1935);

A Text-book of Sound by A. B. Wood (Bell, 1932);

Hearing in Man and Animals by R. T. Beatty (Bell, 1932);

Physical Society of London: Report of a Discussion on Audition (1931);

Physical Society of London: Reports on Progress in Physics. Vol. II, 1935, and Vol. III, 1937;

Modern Acoustics by A. H. Davis (Bell, 1934);

The Acoustics of Orchestral Instruments and of the Organ by E. G. Richardson (Arnold, 1929);

The Acoustics of Buildings by A. H. Davis and G. W. C. Kaye (Bell, 1932);

Collected Papers on Acoustics by W. C. Sabine (Harvard University Press, 1927);

as well as innumerable papers in technical and scientific journals.

On the personal side, I am especially indebted to my wife, to Henry Willis and to Philip Pfaff, Mus. Bac.

J. H. JEANS

Dorking
June 1937

[Pg 1]

CHAPTER I
INTRODUCTION

The Coming of Music

The lantern of science, throwing its light down the long corridors of time, enables us to trace out the gradual evolution of terrestrial life. Far away in the dim distances of the remote past we see it emerging from lowly beginnings—possibly single-cell organisms on the sea shore—and gradually increasing in complexity until it culminates in the higher mammals of to-day, and in man, the most complicated form of life which has so far emerged from the workshop of nature. And as living beings become more complex, they acquire an ever more intricate battery of sense-organs which help them to find their way about the world, to escape danger, to capture their food and avoid being themselves captured as food.

One of these is of special interest to musicians, for out of it has developed our present organ of hearing. Sunk into the skin of a fish, and running the whole length of its body, from head to tail on either side, there is a line of pits or depressions. Under these lies an organ known as the "lateral-line" organ. This is believed to register differences of pressure in the water, which will acquaint the fish with the currents and eddies in which he is swimming, and may also warn him of the proximity of other fish, especially of large fish of hostile intentions.

Even the most primitive fishes seem to have possessed a simple organ of this kind. Gradually the depression nearest[Pg 2] to the head developed into something far more intricate, namely the hard bony structure known as the "labyrinth", which is found in all vertebrates, including ourselves. It consists of hollow tubes filled with fluid, and the main part of it is shaped so as to form three (or in rare cases only one or two) semicircular canals, lying in directions mutually at right angles to one another, as on the right of fig. 1.

Fig. 1. The labyrinth of the left human ear (magnified about 5 times). The three semicircular canals are on the right (d, e, f) and the cochlea on the left (c). a is the oval window to which the ear-drum transmits its vibrations; b is the round window, the function of which is explained below (p. 246).

When an animal turns its head or the upper part of its body, the fluid in the semicircular canals lags behind, because of its inertia, and so rubs over a set of paint-brushes of fine hairs, one in each canal; the bending of these hairs sends a series of nerve-impulses to the brain, which inform it of the change of direction and initiate a set of reflex actions to balance the change. Human beings are seldom conscious that they possess such[Pg 3] organs, although it is by their help that we regain our balance after a sudden slip. They are also responsible for the giddiness we feel after spinning round too often or too rapidly, and for part at least of the even less agreeable sensations we experience when we are on a small ship in a turbulent sea.

A simple equipment of this kind would be adequate for primaeval fish, which lived entirely in the water, but would soon prove inadequate under new conditions which were to come. For the geologists tell us of a period of great drought occurring some 300 million years ago, when seas, lakes and marshes were all drying up. It must have been an anxious time for the fishes, many of which would desert their pools and shallows, and flop across dry land in the hope of finding new water. Clearly the more amphibious they could become, the greater was their chance of survival. In time some of the survivors became pure land-animals—our own ancestry. Organs for registering differences of pressure in water would be of little use to them now. What they needed was an organ to register minute differences of pressure in air, for these were associated with sounds which might indicate the presence of food or of danger, of friends or of enemies.

Gradually the required new organ seems to have developed out of the old. The story of the change provides one of the most fascinating—and, one is almost tempted to say, most incredible—chapters in the evolutionary record. A small area of the bony structure of the labyrinth became thinned down into a yielding membrane of mere skin, thin and soft enough to transmit variations of pressure from the air outside to the fluid within. At the same time, the[Pg 4] labyrinth itself grew in size and increased in complexity. That of the frog shews a small bulge, which, as we proceed farther upwards in the scale of life, gradually develops into the cochlea, which forms the essential part of the ear of vertebrates. The external appearance of this wonderfully intricate piece of apparatus is shewn in fig. 1 on p. 2; its interior is described later (p. 246). For the moment we can only compare it to the case, the sound-board and the strings of a pianoforte of many strings—about 3000 in birds, 16,000 in cats and 24,000 in man—all compressed to the dimensions of less than a pea. It enables its possessor not only to hear sounds, but also to analyse them into their constituent tones. This power ...