r flat will be found by itself, cancelling the
double-sharp or double-flat). The natural is often used when a
composition changes key, as in Fig. 11, where a change from E to G is
shown.

[Footnote 8: It has already been noted (p. 6, Note) that in the German
scale our b-flat is called b, and our b is called H. From this
difference in terminology has grown up the custom of using the H (now
made [natural]) to show that _any_ staff-degree is in _natural_
condition, _i.e._, not sharped or flatted.]

[Illustration: Fig. 11.]

22. The group of sharps or flats (or absence of them) at the beginning
of a staff partially indicates the key in which the composition is
written. They are called collectively the _key-signature_.

23. The same key-signature may stand for either one of two keys, the
major key, or its relative minor, hence in order to determine in what
key a melody is one must note whether the tones are grouped about the
major tonic DO or the minor tonic LA. In a harmonized composition it is
almost always possible to determine the key by referring to the last
bass note; if the final chord is clearly the DO chord the composition is
in the major key, but if this final chord is clearly the LA chord then
it is almost certain that the entire composition is in the minor key.
Thus if a final chord appears as that in Fig. 12 the composition is
clearly in G major, while if it appears as in Fig. 13, it is just as
surely in E minor.

[Illustration: Fig. 12.]

[Illustration: Fig. 13.]

24. Sharps, flats, naturals, double-sharps and double-flats, occurring
in the course of the composition (_i.e._, after the key signature) are
called _accidentals_, whether they actually cause a staff degree to
represent a different pitch as in Fig. 14 or simply make clear a
notation about which there might otherwise be some doubt as in Fig. 15,
measure two. The effect of such accidentals terminates at the bar.

[Illustration: Fig. 14.]

[Illustration: Fig. 15.]

25. In the case of a _tie across a bar_ an accidental remains in force
until the combined value of the tied notes expires. In Fig. 16 first
measure, third beat, an accidental sharp makes the third space represent
the pitch C sharp. By virtue of the tie across the bar the third space
continues to represent C sharp thru the first beat of the second
measure, but for the remainder of the measure the third space will
represent C unless the sharp is repeated as in Fig. 17.

[Illustrat