Quote from "The Artificial Language Movement"

One project, however, did generate considerable interest throughout much of the nineteenth century. Solresol (Langue Musicale Universelle) was an unusually eccentric language even by the standards of universal language projects, and this in all probability accounts for some of its undoubted popularity. It was conceived shortly after the end of the Napoleonic Wars and still had active supporters at the outset of the First World War a century later. The inventor of Solresol, Jean Francois Sudre, was a music master who appreciated that not only was music an international medium but that the seven notes of the "Solfrége" or "Sol-fa" (now somewhat altered in the English forms of the Tonic Sol-Fa), employed for teaching singing, had an internationally-recognised syllabic value: do, re, mi, fa, sol, la, si. He therefore set out to produce a language which would have a vocabulary constructed from these seven syllables alone.

Although Solresol was an a priori language, it was not a philosophical language based upon a logical classification of ideas. Combinations of one or two notes form the particles and pronouns:

Combinations of three notes are used for the most commonly encountered words:

Combinations of four notes are divided into seven classes (called keys) according to the initial note. the key of 'do' includes the physical and moral aspects of man, 're' is used for the family, household, and dress, 'la' for industry and commerce, and so on.

Combinations of five notes furnish the names of the three categories: animal, vegetable, and mineral. And finally, to accommodate proper names, geographical terms, etc., Sudre provided a transcription in notes of the letters of the alphabet. Altogether, Sudre planned to use seven words of one syllable, 49 of two syllables, 336 of three syllables, 2,268 of four syllables, and 9,072 of five syllables. (Comments)

Grammatical categories may be distinguished by the position of an accent over the syllables as follows :

The opposite of an idea is often expressed by reversing the order of the syllables in a word, so:

Based as it was on the musical scale, Solresol could not only be spoken but sung, whistled, or played on a musical instrument. If each syllable was reduced to its first letter (which leaves no ambiguity [what about 'sol' and 'si'? --JS; perhaps 'ti'? -- GdB]) then a kind of shorthand is provided which could be written at speed. Solresol could also serve as a gesture language for the deaf and dumb.