When we hear the diatonic scale we are inclined to say that after every
seven notes the same note recurs, and, asked why we call it the same note
again one might answer, “Well it's a
c again.”
But this isn't the explanation I want, for I should ask,
“What made one call it a
c
again?”
And the answer to this
99.
would seem to be,
“Well, don't you hear that it's the same
tone only an octave higher?” ‒ ‒
Here too we could imagine that a man had been taught our use of the
word “the same” when applied to colours, lengths,
directions, etc., and that we now played the diatonic
scale for him and asked him whether he'd say that he heard the
same notes again and again at certain intervals, and we could easily
imagine several answers, in particular for instance, this, that he heard
the same note alternately after every four or three notes (he calls
the tonic, the dominant, and the octave the same tone).