hen as the chief obstacle to anything like
facility in performance, and without some of this facility he rightly
felt that music must remain a luxury for the few. So genuine was his
interest in the matter, that he was not very careful to fight for the
originality of his own scheme. Our present musical signs, he said, are
so imperfect and so inconvenient that it is no wonder that several
persons have tried to re-cast or amend them; nor is it any wonder that
some of them should have hit upon the same device in selecting the signs
most natural and proper, such as numerical figures. As much, however,
depends on the way of dealing with these figures, as with their
adoption, and here he submitted that his own plan was as novel as it was
advantageous.[326] Thus we have to bear in mind that Rousseau's scheme
was above all things a practical device, contrived for making the
teaching and the learning of musical elements an easier process.[327]

The chief element of the project consists in the substitution of a
relative series of notes or symbols in place of an absolute series. In
the common notation any given note, say the A of the treble clef, is
uniformly represented by the same symbol, namely, the position of second
space in the clef, whatever key it may belong to. Rousseau, insisting on
the varying quality impressed on any tone of a given pitch by the
key-note of the scale to which it belongs, protested against the same
name being given to the tone, however the quality of it might vary. Thus
Re or D, which is the second tone in the key of C, ought, according to
him, to have a different name when found as the fifth in the key of G,
and in every case the name should at once indicate the interval of a
tone from its key-note. His mode of effecting this change is as follows.
The names _ut, re_, and the rest, are kept for the fixed order of the
tones, C, D, E, and the rest. The key of a piece is shown by prefixing
one of these symbols, and this determines the absolute quality of the
melody as to pitch. That settled, every tone is expressed by a number
bearing a relation to the key-note. This tonic note is represented by
one, the other six tones of the scale are expressed by the numbers from
two to seven. In the popular Tonic Sol-Fa notation, which corresponds
so closely to Rousseau's in principle, the key-note is always styled Do,
and the other symbols, _mi_, _la_, and the rest, indicate at once the
relative position of these tones