MUSI C. 
385 
fonant to prelent praftice In mufic, defines modulation, 
1C the manner of eftablilhing and treating a key but 
adds, that the word, at prefent, generally implies the art 
of conducing melody and harmony, fucceflively, into 
many keys, in a manner agreeable to the ear, and accord¬ 
ing to rule. If the key is announced by harmony, it is 
from harmony that the laws of modulation arife. 
Modulation is either natural or abrupt. Natural mo¬ 
dulation is that which takes placejaetween any key and 
another direftly related to it. Abrupt modulation, is a 
fudden change from one key to another not dire&ly re¬ 
lated to it. 
Of Natural Modulation* 
The leading principles of natural modulation may be 
comprehended under the following heads : A compofition 
lhould finifh in the fame key in which it begins ; and, if 
it confift of two or more independent movements, each 
lhould do the fame. A compofition may neverthelefs 
begin in one mode and end in another; that is, it may 
begin in a minor key and conclude in the major of the 
fame name, or vice verfa ; this, however, lhould be con- 
fidered as a licenfe, not to be taken without fome evident 
reafon. In a Ihort compofition, modulation is not infilled 
on, nor even neceflary ; but then it is proper that the 
matter be fufficiently interefting to prevent the encroach¬ 
ment of monotony. 
Every key has five others related, to it, and into either 
of which it may modulate ; thus : 
Any major key can 
modulate into the 
Any minor key can 
modulate into the 
Major Modulations. 
4 5 6 7 
Minor Modulations 
/ part of its fcale. 
Thus the major key cannot modulate into its feventh, 
nor the minor key into its fecond ; as each contains an 
imperfedl or falfe fifth. 
The modulation of any given key, into either of the 
five keys related to it, may be performed .in three diffe¬ 
rent ways : by the difcord of the feventh ; by the perfect 
concord ; or by the chord of the diminifhed feventh. 
1. By the Jevcnth and its inverfions .•—'This modulation 
may be performed either by the chord of the feventh, on 
the fifth of the new key, as at h, Ex. i. (on the back of 
Plate VIII.) or by either of its inverfions, as at i, It, l. 
This Ihows all the four different ways of modulating. 
When the modulation takes place by the chord of the 2 , 
as at l, the refolution of that chord,muft be on the third 
of the new key, with the chord of the fixth, as the fmall 
note at m will Ihow. In this Example will be feen the 
five relative modulations of the given key at i, major and 
minor. Although the feventh only is marked over the 
keys, at n, o, p, q; it muft neverthelefs be underftood, 
that the modulations into thele keys may alfo be performed 
by either of the inverfions of that chord, in the fame 
manner as at h, i, k, l. 
2. By the perfed Concord. —When the fifth (t, Ex. 2.) 
of the new key ( v ) is not immediately preceded by the 
original key (r), but by any other note (as at s'), then 
the fifth ( t ) may carry the perfect concord ; or the fifth 
of the new key ( x ) may be preceded by the new key-note 
itfelf (as at w), or by either of its two inverted chords,, 
(as at y or z.) 
3. By the diminifned Seventh.- —Modulations into minor 
keys may take place by the chord of the diminifhed or 
extreme-flat feventh, as at It h, Ex. 3. or by one of its in¬ 
verfions, as at kit; which indeed is almoft the fame thing 
as performing the modulation by the real feventh 5 for, 
as the diminifhed feventh is a fufpenfion of its own fun¬ 
damental bafs, fo the fundamental bafs of lih and Uk is 
Shat at ii and 11 . 
Having fhown by what means modulation may be per¬ 
formed, it will be now requifite to fliow by what rules it 
is regulated, and how far it may be carried. 
The order , of modulating from one eftabliflied key to 
another, more or lefs related to it, may be comprehended 
under the following general heads: The firft modula¬ 
tion of a major key is into its fifth; this tone being (in 
the fcale) next in influence to the key. The firft modu¬ 
lation of a minor key is into its third major ; for this 
brings the minor key back to the major key on which it 
is eftabliflied. The fecondaiy modulations of a major 
key depend much more on will than on rule; but, before 
return of the original key, the fourth major and fixth mi¬ 
nor are generally introduced. The fecondary modula¬ 
tions of a minor key ftand nearly in the fame circum- 
ftances; but its neareft relative keys are always to be pre¬ 
ferred. Few pieces, however, of confiderable length, 
confine themfelves to relative modulations alone, but go 
into others apparently extraneous. This happens more 
efpecially, when one of the relative keys is confidered as a 
principal; by which a fecond order of keys arifes, colla¬ 
terally relative to the primary key ; or, when the modu¬ 
lation is carried ftill further, then by regarding one of 
thole collateral keys as principal, a third order of keys 
prefents itfelf. But fuch extraneous modulations ought 
to be admitted with great caution, on account of their 
extreme diftance from the original key ; which, if once 
loft fight of, can only be regained in the following man¬ 
ner : either by modulating to one of its relative keys, or 
by means of an enharmonic change, or abrupt modula¬ 
tion. Extraneous modulations may, however, be ufed 
with great efte£i; of this, the works of Haydn, Mozart, 
and other mailers, contain many fine inftances. 
As every key is naturally related to five others, fo each 
of thefe relative keys can only be confidered as one de¬ 
gree, or remove, from the original; conlequently, keys 
which are not relative muft be extraneous. As the rela¬ 
tive minor of every major key is on the fixth tone above, 
and not that of the fame name ; confequently, major and 
minor keys of the fame name are not relative, but extra¬ 
neous. Therefore, if any major key changes immedi¬ 
ately to the minor of the fame name, or vice verfa, the 
modulation is not natural, but abrupt. 
Of Abrupt Modulation. 
Abrupt modulation is a fudden change from one key to 
another not immediately related. This modulation may 
take place either by changing the mode, by omiflion, or 
by an enharmonic change. 
1. By changing the Mode. — If any of the major keys 
contained in the relative modulations of a given key are 
changed into minor, or the minor keys into major, the 
modulation is abrupt. See Ex. 4. The primary or lead¬ 
ing key at A is fuppoled to precede the others at i, It, l, m, n,o, 
immediately ; fo that every ftep it takes is abrupt, not even 
excepting that from h to i, which bears the fame name. 
2. By Omifjion. —.This kind of modulation fuppofes 
fome (omitted) chord between two others to connefl 
them together. See Ex. 5. It muft be evident that fuch 
modulations as thofe from t to v, v to w, w to x, and from 
x to y, can only be admitted by fuppofing the chords ex- 
prefled in the fmall notes to be omitted. This, being 
the leaft agreeable of the abrupt modulations, is the leaft 
ufed. 
3. By changing the Name of any given Note. —This fpe- 
cies of abrupt modulation is of the enharmonic fcale, and 
is founded on the chord of the diminilhed feventh. See 
Ex. 6. where, by changing the name of the bafs of the di¬ 
minilhed feventh at z, to the other bafs z z, a fourth in- 
verfion of a diminilhed leventh is produced; alfo by 
changing the name of the upper part of the inverfion of 
the diminilhed feventh, as at hh, a diminilhed feventh 
itfelf is produced at i i. Although the chords at z, zz 3 
or h h, i i, are the fame in found, yet they are not fo in 
fenfe. See Ex. 7.. 
Th« 
