Pitch (sound)

“ The pitch of sound is wholly determined by the rapidity of the vibration, as the intensity is by the amplitude. What pitch is to the ear in acoustics, colour is to the eye in the undulatory theory of light. ”

“ It consists of the repetition of a vowel sound—generally i (=ee) or e (=a, as in fate) , or a rapid interchange of these two. To the ear of the author the pitch varies through an interval somewhat less than a half-step. Exactly what is the interval he can not say. The musicians to whom appeal for aid in determining this point has been made have either dismissed it for the most part as a matter of little or no consequence or have claimed the seeming variation in pitch was due simply to a changeful stress of voice or of accent. ”

“ This law of sound secures the appropriate resonance for every pitch much more accurately than it could be secured by an effort to develop chest, middle, and head registers through calculating the differences. Again, we need the higher chambers of resonance to reinforce even the low pitch, because every note has its overtones that enrich it, and if these cannot find their proper resonance the tone is impoverished. ”

“ If there is no regular recurrence of waves, it is a noise. The rapidity of these regular beats determines the pitch of tones. That quality or timbre by which one sound is distinguished from another of the same pitch and intensity is due to the different complications of waves in the air; the ability to discriminate the various waves in the vibrating air is, therefore, the condition of our finding music in it; for every wave has its period, and what we call a noise is a complication of notes too complex for our organs or our attention to decipher. ”

“ Thus when we speak of one sound being 'higher in pitch' than another, we mean that the vibrations producing the former are more rapid than those producing the latter, so giving what is recognised as a higher sound. The general nature of this relation may be studied in works on acoustics; it is sufficient here to state that, as a matter of practice, when the exact pitch of any musical sound has to be defined, this is most properly done by stating its vibration-number.
Standard of Pitch. ”

“ The operation of mere sound, disconnected with the ideas which are often conveyed by it, is a subject of curious speculation. Sounds differ from each other in quality, pitch, force, and in length. The difference in tone may be illustrated by the sounds of a clarionet compared with the sound of a bell or of the human voice. Every instrument and every human voice has each a peculiar tone by which it is distinguished from all others. The difference in pitch is shown by sounding a low and a high note in succession on an instrument. ”

“ But almost all ordinary sounds, even those of musical instruments, consist of complex aggregates of undulations of different pitches, and in order to classify the sound we should have to measure the intensities of each of the constituent sounds, a work which has been partially accomplished by Helmholtz, as regards the vowel sounds. The different tones of voice distinctive of different individuals must also be due to the intermixture of minute waves of various pitch, which are yet quite beyond the range of experimental investigation. ”

“ All the vowels do not equally well exemplify in their utterance a distinction of sound in their radical and vanishing movements, because some vowel sounds are less diphthongal than others, and some, again, are pure monophthongs; but these two movements and the concrete variation of pitch, the result of one impulse of the voice, are the essential structure of every syllable, and are characteristic of speech-notes as contradistinguished from those of song. ”

“ The general terms—loudness and quality, embrace all the distinctions heard in a noise, as in the collision of two unelastic sticks. Pitch and duration can scarcely be considered as belonging to common noise. Thus we have— (1) noise whose audible distinctions are comprehended under the general terms loudness and quality; (2) common sound, whose audible distinctions are comprehended under the general terms—loudness, quality, duration, and every varying pitch; (3) musical sound, whose audible distinctions are comprehended under the general terms—loudness, quality, duration, and uniform pitch. ”

“ By this means sounds of higher pitch are produced without actually shortening the length of the column of air by means of lateral holes. The acoustic theory of sound-production in the flute is one on which there is great diversity of opinion. The subject is too vast to be treated here, but readers who wish to pursue it may consult the works of Rockstro, [3] Helmholtz, [4] and others. [5] The effect of boring lateral holes in pipes is to shorten the vibrating length of the air column, which may be regarded as being effective only between the hole in question and the mouthpiece. ”

“ If air from the lungs is sent through the narrow slit, the vocal cords or bands are thrown into rapid vibration and produce sound. The pitch of the sound depends upon the tension of the stretched membranes, and since this can be altered by muscular action, the voice can be modulated at will. In times of excitement, when the muscles of the body in general are in a state of great tension, the pitch is likely to be uncommonly high. ”

“ It is also through the vibrations conveyed by the air to the little membrane called the drum of the ear that the sensations of sound are received, and of the nature of these vibrations a few words must be said presently. In considering the different qualities of sound, we have so far confined ourselves to sustained musical notes, as, for instance, the vowel sounds in singing. This has been done to show the relations of rapidity of vibration to pitch and for simplicity of illustration of the superposition of vibrations, etc. ”

“ When it is once understood that a musical sound is caused by the vibrations more or less frequent which only make the difference we call pitch, it might at once be inferred, that if we have a body that is capable of vibrating say a hundred times a second, and it receives a hundred pulses or pushes a second, it would in this way be made to vibrate. ”

“ Some have finger-holes, enabling the pitch to be altered and give different tones, others have a little ball of clay set loosely in a hollow place, so that when the air is set in motion a shrill whistling sound is emitted. ”

“ First, its intensity, or loudness, which is governed by the height, depth, amplitude—for these amount to the same thing—of the waves produced in the medium. Second, the timbre, or quality, which is regulated by the shape, or outline, of these waves. Third the pitch, high or low, which is controlled by the distance from crest to crest of the sound-waves—or, as we say, from node to node of the vibrations. ”

“ The first one presented to our consideration is the difference between the various instruments, whose invention and elaboration has been found essential to create that totality of musical sound, which in respect to musical sound constitutes a sphere of different tones independently of all distinction of the relation of pitch whether it be a high or a low one. ”

“ The pitch, or the differences of acute and grave, in sounds, form another important property, and one which fits them for a great part of their purposes. By the succession of different notes, we have all the results of melody and harmony in musical sound ”

“ Observations have been made to ascertain the rate at which sound travels through the air ; and the mean result is, that all sounds travel at about the velocity of 1130 feet in a second of time. A musical sound consists of a series of undulations which arrive at the ear at equal intervals of time, and the pitch of the sound depends on the length of the interval between each impression. ”

“ Either by Savart's machine or by the siren, it is proved to demonstration that every musical sound is the product of successive units of sound, each in itself unmusical, which, as they succeed one another with increasing rapidity, produce a tone which progressively rises in pitch. ”

“ The law is without exception throughout the compass in which our ears can distinguish pitch, and so, of necessity, a string of twice the length of that whose vibrations induce the deepest perceivable sound must stir the air at such a rate as to cause a tone at an 8th below that lowest audible note. ”

“ If one reflects upon the possibilities of such a mechanism, and upon the conditions necessary to produce a sound of any given quality, as that of the voice or of a musical instrument as described in preceding pages, he will understand that it can reproduce only pitch. ”

“ Hence a woman’s ordinary pitch in the lower sounds of conversation is more than an octave above a man’s; in the higher sounds it is two octaves.
And here it is important to note that by the term vibrations is meant complete ones; and by the term sonorous wave is meant a condensation and its associated rarefaction. By a vibration an excursion to and fro of the vibrating body is to be understood. Every wave generated by such a vibration bends the tympanic membrane once in and once out. These are the definitions of a vibration and of a sonorous wave employed in England and Germany. ”

“ Sound possesses a musical quality only when the waves or pulses follow each other at absolutely regular intervals.
262. The Effect of the Rapidity of Motion on the Musical Tone Produced. If the disk is rotated so slowly that less than about 16 puffs are produced in one second, only separate puffs are heard, and a musical tone is lacking; if, on the other hand, the disk is rotated in such a way that 16 puffs or more are produced in one second, the separate puffs will blend together to produce a continuous musical note of very low pitch. ”

“ But, as these shorter vibrations are quicker, they yield notes of a higher pitch, which mingle with the fundamental note, and alter its quality. These accompanying higher notes may be in harmony with the fundamental note (when they are called harmonics) , or they may not harmonize with it. The sounds emitted by the parts of a vibrating body are called overtones, and it is possible for a string to furnish as many as 20 or 30 of these. The mingling of the overtones with the fundamental one determines the timbre of sound. ”

“ The third quality of sound is due to the form of the vibrations regardless of the pitch or the loudness. The trained ear recognizes, for instance, in the note of the tuning fork, the violin, the clarionet and the piano, the same tone howsoever made. ”

“ The cycle of movement will then be repeated numerous times per second, with the result that a very pure foundation tone musical note will be produced.
The Diaphone is tuned like ordinary flue pipes and will keep in tune with them; the pressure of wind (and consequently the power of the tone) may be varied without affecting the pitch. The form of the pipe or resonator affects the quality of the tone; it may be flue-like or reedy in character, or even imitate a Pedal Violone, a Hard and Smooth Tuba, an Oboe, or a Clarinet. ”

“ Not only is it more rhythmical, but it is more musical; that is to say, though the pitch is not deliberately regulated, as in song, there is a tendency to a level monotonous intonation, and changes of pitch, when they occur, are more conscious and more noticeable. ”

“ A person with an untrained ear can appreciate music comparatively little, even though he is well educated in the theory of music. Absolute pitch is the ability to recognize and intonate any tone indicated. Very few persons possess naturally absolute pitch, but it may be acquired by a systematic study of ear training. Relative pitch is the ability to recognize a tone by comparison with a known tone. Advancement in relative pitch eventually leads to the attainment of absolute pitch. ”

“ To practise this, dwell on various voiced sounds for a long time, emitting the breath slowly and regularly.
Only the voiced sounds can be produced with varying pitch; they are musical, the rest are noises. Notice, in church for instance, how the tune is carried by the voiced sounds; the voiceless ones seem to break the course of the tune.
When the vocal chords are short they vibrate more quickly than when they are long, and quicker vibrations give a higher pitch. This explains why the average pitch of a woman's voice is higher than that of a man. ”

“ You will find that the string tuned to the pitch of your voice will start vibrating while all the others remain quiet. You can even go farther and try the experiment of uttering several different pitches, if you want to, and the corresponding strings will give back your notes, each one singling out its own particular vibration from the air. Now the results reached in these experiments with the piano strings meant a great deal more to Alexander Graham Bell than they would have meant to you or to me. ”

“ The reciprocal principle of elective affinity between fundamental and overtone, between the shape assumed by the larynx for pitch and the shape assumed by the resonance-cavities for quality, is illustrated by the exciting influence of a sounding instrument upon a silent one tuned to the same pitch which, although not touched by human hand, sounds in sympathy with the one that is being played on. ”

“ For here, when the pitch shifts, the voice, by change of position, stations itself on one pitch, then on another, and, as it frequently repeats this alternating process, it appears to the senses to become stationary, as happens in singing when we produce a variation of the mode by changing the pitch of the voice. ”