who has to find his note upon the string, than in that of the pianist who has each note definitely settled for him by the keyboard. The great advantage of this three-colour system is that almost infinite gradation as to intensity, and some approach to infinity as to variety of tint, can be obtained by its means; but, except for extemporization, it is, strange to say, much more difficult to use than the colour-organ of the keyboard type. A composition in colour can be written for it, either upon the musical method or in various other ways.
In using any but the musical method, however, the difficulty of easily expressing the duration of a note has to be overcome, or showing whether it is long or short, or accentuated, and so forth. An example is given below of the method of notation employed.
Each space represents a given note as indicated by its number on the index scale, and the length of the space determines the relative length of the note in the bar. The letters R. Y. and B. are the initials of the primaries.
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