d, whether the melody proposed to
repose upon re, upon fa or do. The usual points of repose in Greek
music were mi, fa and re; never upon do, the real key tone, and rarely
upon la, the natural tonic of the minor mode.

One of the chief elements of modern musical expression, particularly
in the expression of melody, is the unconscious perception of the
"relation of tones in key." With every tone sung the singer conceives
not only that tone, its predecessor and its follower, but all other
tones in the entire course of the melody; and the expression of every
tone in the series rests upon its place in rhythm, and still more upon
its "place in key." Change a single tone in a melody, as, for
instance, to make fa a half step sharp, and the expression of the
entire melody is thereby changed, until such time as the hearer has
forgotten the change of key effected by the introduction of the
foreign tone. It is not at all unlikely that what little of melodic
expression the music of the Greeks had, may have rested to some extent
upon an unconscious perception of these relations, which, although
foreign to their musical theory, may nevertheless have made their way
into the ears of these acute minstrels. The discovery of simple
tonality seems to have been due to the northern minstrels, for it is
here that we find the earliest melodies purely tonalized. But the
natural bounds of a melodic tonality as established by these northern
harpers have been very much exceeded in modern times, so that now
there is hardly a chord possible which might not be introduced in the
course of a composition in any key whatever, without effecting a
digression into the new key suggested by the strange chord. Not only
all the natural or diatonic notes are regarded as belonging to a key,
but also all the chromatics, the sharps and flats, and the double
sharps and double flats.

All this implies a growth of tonal perception on the part of the
hearers, and especially of the ability to co-ordinate tonal
impressions over a wide and constantly increasing range. For the
hearer has in mind not only the particular tone which at the moment
occupies his ear, and the others which preceded it, and a sort of
inner feeling of the tone which will follow the present one, but also
all the other tones over which the singer would pass in going from one
tone to another. And unless he has this he cannot realize the true
place of the melody tone in key, and therefore rests uncons