In regard to the lower bridge, the strings will rarely "render"

through them properly unless brought to a tension a little higher than

it is desired they shall be left. If this is done, a few sharp blows

of key will generally make them equalize all right; then press the

hammer gently to the left, not enough to turn the pin in the socket,

but to settle it back to a well-balanced position. After a little

practice the tuner can generally guess precisely how much

over-tension to allow. If the pin is left slightly sprung downward,

its tendency will be to spring upward, thereby sharpening the string;

so be careful to leave the pins in perfect balance, or as tuners say,

"properly set."

The foregoing, while applicable to the whole scale, is not so urgent

in the over-strung bass. The strings are so heavy and the tension is

so great that they will generally "render" quite freely over the

bridges, and it is only necessary to bring them up to pitch, handling

the hammer in such a manner as to leave the pins well balanced; but it

is not necessary to give them over-tension and beat them down again;

in fact it is not advisable, as a rule. At all times, place the hammer

on the pin as far as it will go, and strike the key while drawing a

string up.

In tuning the square piano, it is not possible to set the hammer upon

the pin with the handle in line with, and beyond the string, as is the

rule in the upright. Where the square has the square pin, the hammer

(with star head) can always be set with the handle to the right of the

string somewhat, but usually almost in line with the string and almost

directly over it, and the manipulation of the hammer is much the

same, though the tuner is at a greater disadvantage, the pins being

farther from him and he has not such a good rest for his hand. Many

old squares have the oblong pin. In this case, use the double hammer

head. On the one side the hole in the head is made with the longer

diameter in line with the handle, and on the other side the hole is

made with the longer diameter at right angles with the handle; so that

if you cannot get a favorable position with one end you can with the

other.

We have said nothing about which hand to use in striking the keys and

in wielding the hammer, but it is customary to handle the hammer with

the right hand and it is always advisable for two very good reasons:

It gives the tuner a much more favorable position at the instrument;

and, as the right hand is more used in ordinary every-day operations

and is more trained in applying degrees of force and guiding tools, it

is more easily trained to manipulate the hammer properly. Training the

hand in the skilful use of the hammer is of the utmost importance and

comes only by continued practice, but when it is trained, one can

virtually "feel" the tones with the hammer.

At first, the young tuner is almost invariably discouraged by his slow

progress. He must remember that, however fine his ear and however

great his mechanical ability, he has much to acquire by training in

both, and he must expect to be two or three times longer in finishing

off a job of tuning at the outset than will be necessary after he has

had a few months' practice. You can be your own trainer in these

things if you will do a little rational thinking and be content to

"hasten slowly." And as to using the left hand, we would not advise it

in any event.

SETTING THE MUTES OR WEDGES IN THE UPRIGHT.

As stated in a previous lesson, the mutes should be so placed that

only two strings are heard at one time: the one the tuner is tuning,

and the one he is tuning by. It is true that this is an easy matter,

but it is also true that very few tuners know how to do it in a way to

save time and avoid placing the mutes two or more times in the same

place. By using a little inventive genius during early practice the

author succeeded in formulating a system of muting by which he

accomplished the ends as stated above, and assures the reader that a

great deal of time can be saved by following it.

After removing the muffler or any other instrumental attachment which

may be in the piano in the way of placing the mutes, the first thing

to do is to place the continuous mute so that all the outside strings

of the trios are damped. The temperament is then set by tuning the

middle strings, of the twenty-five trios comprised in the two-octave

temperament as demonstrated in a previous lesson. After satisfying

yourself by trials or test that the temperament is true, you then

remove the continuous mute and proceed to bring the outside strings in

unison with the middle one. Now, your 1C is sometimes found to be the

first pair in the over-strung bass, which usually has two strings to a

key, while in other pianos, 1C is the first trio in the treble

stringing, and in many cases it is the second trio in the treble. For

illustration, we will say it is the second in the treble. In speaking

of the separate strings of a trio we will number them 1st, 2d, and 3d,

from left to right, as in foot-note, page 89, Lesson IX. Setting the

mutes in bringing up the unisons in the temperament is exceedingly

simple.

The following diagram will, we think, demonstrate clearly the method

employed:

Upper row---- o o o o o o o o o o Tim-

Middle row--- o o o o o o o o o o ing

Lower row---- o o o o o o o o o o Pins.

------------------------------------------ Bridge.

* 1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * &c

/// /// /// /// /// /// /// /// /// /// Treble stringing.

B C C♯ D D♯ E F F♯ G G♯ &c

The upper row of O's represents the upper row of tuning pins. To these

are attached the first string of each unison. To the middle row are

attached the second or middle strings, and to the lower row are

attached the third strings. The diagonal lines represent the three

strings of the unison (trio). The asterisk on the middle one indicates

that it has been tuned.

But one mute is used in tuning these unisons. It is inserted between

the trios in the order indicated by the figures 1, 2, 3, etc. When

inserted in place 1, between unisons B and C, it will mute the first

string of C; so the first string of the trio to tune is always the

third. Then place your mute in place 2 and tune the first string of C.

Then, without moving your mute, bring up third string of C♯, then

third string of D and so on. By this method, you tune two strings

every time you reset your mute.

When through with the temperament, the next step is usually that of

tuning the bass; but while we are in the treble we will proceed to

give the method of setting the mutes in the upper treble beyond the

temperament. All three strings have yet to be tuned here, and we have

to use two mutes. The unisons are tuned in regular succession upward

the same as in the example above. The mute that is kept farthest to

the left, is indicated by the letter A, and the one kept to the right,

by the letter B, as in diagram below.

(T e m p e r a m e n t ) 1 2 3 4 5 6 7 &c.

*** *** *** *** *** *** A B

/// /// /// /// /// /// /// /// /// /// /// /// /// ///

C♯ D D♯ E F F♯ G &c.

The mutes are first placed in the places indicated by the figures 1

and 2, thereby muting first and third strings of the first unison

beyond the temperament, which is 3C♯. The middle string of this unison

is now tuned by its octave below. (If you have left imperfect unisons

in your temperament, rendering it difficult to tune octaves by them,

it will be well to replace your continuous mute so as to tune from a

single string.) Having tuned the middle string of C♯, move mute B to

place 3 and tune third string of C♯. Then, move mute A to place 2 and

tune first string of C♯. Your mutes are now already set for tuning the

middle string of D. After this is done, proceed to move mute B first,

then mute A; tuning middle string, then third, then first, moving step

by step as indicated in example above until the last unison is

reached. By this system you tune three strings every time the mutes

are set twice.

The over-strung bass usually has but two strings to a unison and only

one mute is needed. In the extreme low or contra-bass, pianos have but

one string, in tuning which the mute is discarded. Set the mute as

indicated by the figures 1, 2, 3, etc., in the diagram below, always

tuning the string farthest to the right by its octave above; then move

the mute to its next place and tune the left string by the right.

Here, again, you tune two strings every time you reset your mute. The

I's represent bass strings.

9 8 7 6 5 4 3 2 1

I I I I I I I II II II II II II II II II

C C♯ D D♯ E F F♯ G G♯ A A♯ B C

Contra-Bass. Bass. Treble.

SETTING THE MUTES IN THE SQUARE PIANO.

In setting the temperament in the square piano, simply mute the string

farthest to the left and tune the one to the right until the

temperament is finished, then set the mutes in the bass the same as in

the upright. In tuning the treble, if the piano has three strings, the

same system is used as has been described for the upright. When the

piano has but two strings to a unison, as is usually the case, employ

the system described for the bass of the upright, but reversed, as you

are proceeding to the right instead of to the left.

Remove the shade before beginning to tune a square piano, and if

necessary, lay the dampers back and trace the strings to their pins so

as to mark them. Certain pins are marked to guide the tuner in placing

his hammer. The way we have always marked them is as follows:

Mark both pins of each pair of C strings with white crayon. Mark only

one pin of each pair of G's. Knowing the intervals of the other keys

from the marked ones, you can easily calculate correctly, upon which

pin to set your hammer to tune any string desired. For instance, if

you are striking D♯, next above middle C, you calculate that, as D♯ is

the third chromatic interval from middle C, you are to set the hammer

on one or the other of the pins belonging to the third pair to the

right of the pair marked as middle C. B would be first pair to the

left, F♯ would be first pair to the left of the marked G, and so on.

It is usually necessary to mark only those pairs near the middle of

the piano, but we advise the beginner to mark throughout the scale, as

by so doing he may avoid breaking a string occasionally by pulling on

some other than the one he is sounding. This will occur in your early

practice if you do not use caution. And for safety, some tuners always

mark throughout.

QUESTIONS ON LESSON XI.

1. By what means is the tuner enabled to make the strings draw

through the bridges and equalize the tension throughout their

entire length?

2. State conditions that may result from a tuning pin's not being

properly set.

3. In this system of muting, state definitely which string is

tuned first after the continuous mute is removed. Which second?

Which third?

4. After the unisons are finished in the temperament, which string

is tuned next, if we go immediately from the temperament to the

over-strung bass? Which second? Which third?

5. Upon beginning to tune the treble beyond the temperament, which

string is tuned first? Which second? Which third?

6. (a) How many mutes are used in tuning outside the strings of

the temperament?

(b) In what proportion is the number of times the mute is

changed to the number of strings tuned?

7. (a) How many mutes are used in tuning the treble beyond the

temperament?

(b) In what proportion is the number of times the mute is

changed to the number of strings tuned?

8. Which pairs of pins are marked in the square piano to guide the

tuner in placing his hammer? Also, how are they marked?

9. Having marked your pins as instructed, how would you find the

pins belonging to a pair of strings struck by F on key-board? How

those struck by G♯?

10. Tell what you can of the requirements necessary to insure that

a piano will stand in tune.

LESSON XII.

~MATHEMATICS OF THE TEMPERED SCALE.~

One of the first questions that arises in the mind of the thinking

young tuner is: Why is it necessary to temper certain intervals in

tuning? We cannot answer this question in a few words; but you have

seen, if you have tried the experiments laid down in previous lessons,

that such deviation is inevitable. You know that practical scale

making will permit but two pure intervals (unison and octave), but you

have yet to learn the scientific reasons why this is so. To do this,

requires a little mathematical reasoning.

In this lesson we shall demonstrate the principles of this complex

subject in a clear and comprehensive way, and if you will study it

carefully you may master it thoroughly, which will place you in

possession of a knowledge of the art of which few tuners of the

present can boast.

In the following demonstrations of relative pitch numbers, we adopt a

pitch in which middle C has 256 vibrations per second. This is not a

pitch which is used in actual practice, as it is even below

international (middle C 258.65); but is chosen on account of the fact

that the various relative pitch numbers work out more favorably, and

hence, it is called the "Philosophical Standard." Below are the actual

vibration numbers of the two pitches in vogue; so you can see that

neither of these pitches would be so favorable to deal with

mathematically.

International--3C--517.3. Concert--3C--540.

(Let us state here that the difference in these pitches is less than a

half-step, but is so near that it is generally spoken of as being just

a half-step.)

Temperament denotes the arrangement of a system of musical sounds in

which _each one_ will form a serviceable interval with _any one_ of

the others. Any given tone must do duty as the initial or key-note of

a major or of a minor scale and also as any other member; thus:

C must serve as 1, in the key of C major or C minor.

" " 2, " " B♭ " B♭ "

" " 3, " " A♭ " A "

" " 4, " " G " G "

" " 5, " " F " F "

" " 6, " " E♭ " E "

" " 7, " " D♭ " C♯ "

Likewise, all other tones of the instrument must be so stationed that

they can serve as _any member_ of _any scale_, major or minor.

This is rendered necessary on account of the various modulations

employed in modern music, in which every possible harmony in every key

is used.

RATIONALE OF THE TEMPERAMENT.

Writers upon the mathematics of sound tell us, experience teaches us,

and in previous lessons we have demonstrated in various ways, that if

we tune all fifths perfect up to the seventh step (see diagram, pages

82, 83) the last E obtained will be too sharp to form a major third to

C. In fact, the third thus obtained is so sharp as to render it

offensive to the ear, and therefore unfit for use in harmony, where

this interval plays so conspicuous a part. To remedy this, it becomes

necessary to tune each of the fifths a very small degree flatter than

perfect. The E thus obtained will not be so sharp as to be offensive

to the ear; yet, if the fifth be properly altered or tempered, the

third will still be sharper than perfect; for if the fifths were

flattened enough to render the thirds perfect, they (the fifths) would

become offensive. Now, it is a fact, that the third will bear greater

deviation from perfect consonance than the fifth; so the compromise

is made somewhat in favor of the fifth. If we should continue the

series of perfect fifths, we will find the same defect in all the

major thirds throughout the scale.

We must, therefore, flatten each fifth of the complete circle,

C-G-D-A-E-B-F♯-C♯-G♯ or A♭-E♭-B♭-F-C, successively in a very small

degree; the depression, while it will not materially impair the

consonant quality of the fifths, will produce a series of somewhat

sharp, though still agreeable and harmonious major thirds.

We wish, now, to demonstrate the cause of the foregoing by

mathematical calculation, which, while it is somewhat lengthy and

tedious, is not difficult if followed progressively. First, we will

consider tone relationship in connection with relative string length.

Students who have small stringed instruments, guitar, violin, or

mandolin, may find pleasure in demonstrating some of the following

facts thereupon.

One-half of any string will produce a tone exactly an octave above

that yielded by its entire length. Harmonic tones on the violin are

made by touching the string lightly with the finger at such points as

will cause the string to vibrate in segments; thus if touched exactly

in the middle it will produce a harmonic tone an octave above that of

the whole string.

Two-thirds of the length of a string when stopped produces a tone a

fifth higher than that of the entire string; one-third of the length

of a string on the violin, either from the nut or from the bridge, if

touched lightly with the finger at that point, produces a harmonic

tone an octave higher than the fifth to the open tone of that string,

because you divide the string into three vibrating segments, each of

which is one-third its entire length. Reason it thus: If two-thirds of

a string produce a fifth, one-third, being just half of two-thirds,

will produce a tone an octave higher than two-thirds. For

illustration, if the string be tuned to 1C, the harmonic tone produced

as above will be 2G. We might go on for pages concerning harmonics,

but for our present use it is only necessary to show the general

principles. For our needs we will discuss the relative length of

string necessary to produce the various tones of the diatonic scale,

showing ratios of the intervals in the same.

In the following table, 1 represents the entire length of a string

sounding the tone C. The other tones of the ascending major scale

require strings of such fractional length as are indicated by the

fractions beneath them. By taking accurate measurements you can

demonstrate these figures upon any small stringed instrument.

Funda- | Major | Major | Perfect | Perfect | Major | Major | Oc- |

mental |Second | Third | Fourth | Fifth | Sixth | Seventh | tave |

| | | | | | | |

C | D | E | F | G | A | B | C |

1 | 8/9 | 4/5 | 3/4 | 2/3 | 3/5 | 8/15 | 1/2 |

To illustrate this principle further and make it very clear, let us

suppose that the entire length of the string sounding the fundamental

C is 360 inches; then the segments of this string necessary to produce

the other tones of the ascending major scale will be, in inches, as

follows:

C | D | E | F | G | A | B | C |

360 | 320 | 288 | 270 | 240 | 216 | 192 | 180 |

Comparing now one with another (by means of the ratios expressed by

their corresponding numbers) the intervals formed by the tones of the

above scale, it will be found that they all preserve their original

purity except the minor third, D-F, and the fifth, D-A. The third,

D-F, presents itself in the ratio of 320 to 270 instead of 324 to 270

(which latter is equivalent to the ratio of 6 to 5, the true ratio of

the minor third). The third, D-F, therefore, is to the true minor

third as 320 to 324 (reduced to their lowest terms by dividing both

numbers by 4, gives the ratio of 80 to 81). Again, the fifth, A-F,

presents itself in the ratio of 320 to 216, or (dividing each term by

4) 80 to 54; instead of 3 to 2 (=81 to 54--multiplying each term by

27), which is the ratio of the true fifth. Continuing the scale an

octave higher, it will be found that the sixth, F-D, and the fourth,

A-D, will labor under the same imperfections.

The comparison, then, of these ratios of the minor third, D-F, and the

fifth, D-A, with the perfect ratios of these intervals, shows that

each is too small by the ratio expressed by the figures 80 to 81. This

is called, by mathematicians, the _syntonic comma_.

As experience teaches us that the ear cannot endure such deviation as

a whole comma in any fifth, it is easy to see that some tempering must

take place even in such a simple and limited number of sounds as the

above series of eight tones.

The necessity of temperament becomes still more apparent when it is

proposed to combine every sound used in music into a connected system,

such that each individual sound shall not only form practical

intervals with all the other sounds, but also that each sound may be

employed as the root of its own major or minor key; and that all the

tones necessary to form its scale shall stand in such relation to each

other as to satisfy the ear.

The chief requisites of any system of musical temperament adapted to

the purposes of modern music are:--

1. That all octaves must remain perfect, each being divided into

twelve semitones.

2. That each sound of the system may be employed as the root of a

major or minor scale, without increasing the number of sounds in

the system.

3. That each consonant interval, according to its degree of

consonance, shall lose as little of its original purity as

possible; so that the ear may still acknowledge it as a perfect or

imperfect consonance.

Several ways of adjusting such a system of temperament have been

proposed, all of which may be classed under either the head of equal

or of unequal temperament.

The principles set forth in the following propositions clearly

demonstrate the reasons for tempering, and the whole rationale of the

system of equal temperament, which is that in general use, and which

is invariably sought and practiced by tuners of the present.

PROPOSITION I.

If we divide an octave, as from middle C to 3C, into three major

thirds, each in the perfect ratio of 5 to 4, as C-E, E-G♯ (A♭), A♭-C,

then the C obtained from the last third, A♭-C, will be too flat to

form a perfect octave by a small quantity, called in the theory of

harmonics a _diesis_, which is expressed by the ratio 128 to 125.

EXPLANATION.--The length of the string sounding the tone C is

represented by unity or 1. Now, as we have shown, the major third to

that C, which is E, is produced by 4/5 of its length.

In like manner, G♯, the major third to E, will be produced by 4/5 of

that segment of the string which sounds the tone E; that is, G♯ will

be produced by 4/5 of 4/5 (4/5 multiplied by 4/5) which equals 16/25

of the entire length of the string sounding the tone C.

We come, now, to the last third, G♯ (A♭) to C, which completes the

interval of the octave, middle C to 3C. This last C, being the major

third from the A♭, will be produced as before, by 4/5 of that segment

of the string which sounds A♭; that is, by 4/5 of 16/25, which equals

64/125 of the entire length of the string. Keep this last fraction,

64/125, in mind, and remember it as representing the segment of the

entire string, which produces the upper C by the succession of three

perfectly tuned major thirds.

Now, let us refer to the law which says that a perfect octave is

obtained from the exact half of the length of any string. Is 64/125 an

exact half? No; using the same numerator, an exact half would be

64/128.

Hence, it is clear that the octave obtained by the succession of

perfect major thirds will differ from the true octave by the ratio of

128 to 125. The fraction, 64/125, representing a longer segment of the

string than 64/128 (1/2), it would produce a flatter tone than the

exact half.

It is evident, therefore, that _all major thirds must be tuned

somewhat sharper than perfect_ in a system of equal temperament.

The ratio which expresses the value of the _diesis_ is that of 128 to

125. If, therefore, the octaves are to remain perfect, which they must

do, _each major third must be tuned sharper than perfect by one-third

part of the diesis_.

The foregoing demonstration may be made still clearer by the following

diagram which represents the length of string necessary to produce

these tones. (This diagram is exact in the various proportional

lengths, being about one twenty-fifth the actual length represented.)

Middle C (2C) 60 inches.

--------------------------------------------------

O O

E (4/5 of 60) 48 inches.

--------------------------------------------

O O

G♯ (A♭) (4/5 of 48) 38-2/5 inches.

--------------------------------------

O O

3C (4/5 of 38-2/5) 30-18/25 inches.

--------------------------------

O O

This diagram clearly demonstrates that the last C obtained by the

succession of thirds covers a segment of the string which is 18/25

longer than an exact half; nearly three-fourths of an inch too long,

30 inches being the exact half.

To make this proposition still better understood, we give the

comparison of the actual vibration numbers as follows:--

Perfect thirds in ratio

4/5 have these vibration

numbers: =

1st third 2d third 3d third

(C 256 - E 320) (E 320 - G♯ 400) (G♯ 400 - C 500)

--------------- ----------------- -----------------

no beats no beats no beats

Tempered thirds qualified

to produce true

octave: =

(C 256 - E 322 5/10) (E 322 5/10 - G♯ 406 4/10) (G♯ 406 4/10 - C 512)

-------------------- -------------------------- ----------------------

10 beats 13-1/10 beats 16 beats

We think the foregoing elucidation of Proposition I sufficient to

establish a thorough understanding of the facts set forth therein, if

they are studied over carefully a few times. If everything is not

clear at the first reading, go over it several times, as this matter

is of value to you.

QUESTIONS ON LESSON XII.

1. Why is the pitch, C-256, adopted for scientific discussion, and

what is this pitch called?

Piano tuning · 第 5 / 8 段