8. INTERVALS

(Table 8)

8.1. When two or more notes of the same value are sounded together, forming a chord, one note only is written according to Table 1, the remainder being represented by the signs in Table 8 which indicate their distance, or interval, from the written note.

8.2. The direction in which intervals are to be read (upward or downward from the written note) depends very much on the instrument for which the music is written, and on the disposition of the score. In general, it may be said that the melody and the bass should each appear as written notes. Where clef signs are used, the treble clef implies a downward reading and the bass clef an upward reading of intervals.

(When it is desired to reverse the usual normal practice in reading intervals and in-accords in any part, one of the following indications

7Y/ EQUALS Y<>Z<K7
7Y/ EQUALS Y<>)<K7

should be placed at the beginning of the piece. Where necessary, this indication can be preceded by a hand sign, the initials of an instrument, etc.)

Example 8.2-1.
#D4
.>.?0 "W+[+\#\9 "[0W#?0<K
_>_?9 _$+]9\+$0 _]+:+?9<K



(See also Par. 20.4, 26.8, 28.11-28.12.)

8.3. When the written note is dotted, it is not necessary to place dots after any intervals (but see Example 8.8.4-1).
Example 8.3-1.

#D4
.>.?'0E9F'+=+F'+Z9
.?''0"(+\+V<K


8.4. Intervals larger than the octave are expressed by the same series of signs preceded by an appropriate octave mark, the 9th corresponding to the 2nd, the 10th to the 3rd, and so on.

Example 8.4-1.

#C4
.>.\_0\_3]_9 .P'"+<K




8.5. The octave rules for chords of more than two notes are as follows:

8.5.1. If more than one interval follows the written note, no octave mark is needed so long as any two adjacent intervals are less than an octave apart.

Example 8.5-1.
#C4
.>.\-0\-3]39 .P'0+<K



Example 8.5-2.

#C4
.>.\-#0\9+3]+39 .P'+0+<K


8.5.2. If any two adjacent intervals are an octave or more apart, the second interval must have its proper octave mark.
Example 8.5.2-1.

#C4
.>.\#_0\9_3]+_9 .P'+"+<K


8.5.3. If an interval forms a unison with the written note, it is shown as an octave preceded by its proper octave mark.

Example 8.5.3-1.

#C4
.>.\.-_0\9_3]+_9 .P'.-"+<K



8.5.4. If an interval forms a unison with another interval the second interval must have its proper octave mark.

(N. B. In the last two chords of the following example the inner parts form an octave in the one case and a unison in the other).
Example 8.5.4-1.

#C4
.>.\-0_0\+"93]+"+9 .P'0"0+<K



8.5.5. When two parts represented by intervals cross one another in a chord, each note that is, so to speak, out of place must have its proper octave mark, the written order of the parts however remaining unchanged.

Example 8.5.5-1.

#C4
.>.\-#0\"9"+3]"+"39 .P'0+"+<K





Tone Clusters

8.6. Tone clusters are notated in many different ways, but usually the top and bottom pitches are written as if they are pitches in a chord. Between the two pitches, a vertical line, box, thick bar, or other shape indicates the cluster. Accidentals or printed words may or may not accompany the cluster.

8.6.1. According to the proper direction of intervals, the top or bottom pitch is written followed by the cluster sign and an interval sign showing the other outside pitch.
Example 8.6.1-1.
(a) _>'*^I^*B*-
(b) .>.\^%B"/
(c) .>.Q^5B-

Doubling of Intervals

8.7. When more than three successive notes are followed by the same interval or intervals not modified by accidentals or other signs, such intervals may be doubled.

Example 8.7-1.

#D4
_>^D--EFGHIJH _DJIHGFED-<K


8.7.1. If, during a passage of such doubling, any doubled interval, except for octaves, is modified, the doubling of that interval must be re-marked where the accidental occurs if its continuance is justified. Thus, the doubling of an interval may be initiated, as well as re-marked, at the point of modification, provided that the modified, doubled interval is followed by at least three unmodified, like intervals. Doubling which is in progress must also be restated when yet another interval warrants doubling under the usual conditions. If, during said passage, any doubled interval is terminated, the doubling of any other interval should be terminated simultaneously, unless its continuance is justified, in which case the interval is redoubled at that point, thus:

Example 8.7.1-1.

#F8
.>"H .D##00JDEFG .HIJDEF
;]#00F+]#F+ ;:/%0XV<K



8.7.2. When greater-than-octave intervals are involved, it is inadvisable to use any doubling of intervals whatsoever. The necessity to insert appropriate octave marks for each such interval, in the absence of intermediary intervals, would usually negate any supposed saving of space.
Example 8.7.2-1.

#B4
Poor:

_>.C^(99D_/Y_/.CY_/D93Y-<K

Good:
_>.C^(9D9/Y9/.CY9/D93Y-<K


8.7.3. In a passage of doubled octaves the doubling need not be interrupted by the occurrence of accidentals which would normally be marked for the octave as well as for the written note.

Example 8.7.3-1.

<<<#B4
_>'<^\<--$ <^:'<D @J<H*^DI-<K


8.7.4. All doubling of intervals legitimately in effect at the end of the previous page should be restated at the beginning of a new page, assuming that at each instance there are a sufficient number of notes to warrant such doubling. Thus, doubling will not be started at the bottom of the page unless it can legitimately be in effect on that page, nor will it be employed at the top of the page if the usual conditions do not prevail.

8.7.5. In fingered music it is not advisable to double any other interval than the octave unless every note of the passage is fingered or unless the fingering is so placed that there can be no possible doubt about the notes to which it belongs.

(See also Par. 15.2.1 and Example 17.5-1.)



The Moving-Note Sign

8.8. The moving-note device, although infrequently employed, is chiefly useful for vocal music and keyboard settings of hymns. Complications of fingering, phrasing and nuances render it unsuitable for instrumental music in general.

8.8.1. When two, or at most three, notes of equal value move below or above a longer note, they can be written as intervals separated by dot 6.

(In the following example the first two intervals are halves and the remainder quarters).
Example 8.8.1-1.

#D4
.>.(+,9 .R'+,#,9V<K

8.8.2. The moving-note sign can also be used when two or more intervals move together in a similar manner but in this case dots 5-6 must be substituted for dot 6.
Example 8.8.2-1

#D4
.>.(+9;9+ .R'+9;#-;9+V<K

8.8.3. The marking of octaves in the moving part is governed by the rule given in Par. 8.4. Compare (a) and (b) below.

Example 8.8.3-1.

<<<#F8
(a) .>.]'-,<+,-$'0,+,*9<K



(b) .>"G<.E"GH.D*I<K



8.8.4. The moving-note sign can also be used for a dotted quarter and eighth, etc., but is not recommended for such a rhythm as that shown at (b) below.

Example 8.8.4-1.

#D4
(a) Good: .>"P+',#Q0',9 "&+<K


(b) Bad: .>"P+,#'Q0,9' "&+<K



The doubled moving-note sign (dots 5-6) must never be used for such dotted rhythms.