Ya know how to whistle, doncha?

Solresol was an early nineteenth century constructed language, based  (as you might expect, if you don't see "sun" in the name) of the solfeggio syllables do, re, mi, fa, sol, la, ti. It appears to be the first constructed language actually to be constructed rather than merely sketched out for philosophical  consideration.  It enjoyed a brief period of popularity just before and during  Volapu"k and then early Esperanto.  There have been occasional efforts to revive or revise it since, but mainly, it has dropped from memory.  I suspect that Carnap, who once whistled a sentence in class, was among the last of reasonably original users.

As that anecdote notes, the virtue of Solresol was that it was multimedia: it could be sung or whistled or played on an instrument as well as spoken and written.  And its limited number (7) of syllables also opens the way for a number of shorter writing systems as well as various signalling devices (sign language, semaphore, and so on) without too much additional learning.  Even colors -- the seven of the rainbow -- and numbers could be used, meaning Solresol text was everywhere, did you but look. Remember the plurality of modes -- sound, color, hand gestures -- employed by aliens and professors in Close Encounters.



One problem with the original was that, since there were so few syllables, any confusions about word boundaries would lead to catastrophic miscommunication. So every word had to be surrounded by appreciable silence or space, which is both aesthetically unappealing and hard to do in practice.  (The musical version also had the problem that notes in isolation are not easily assigned their solfege roles until the whole octave is known, not always easy to do in a natural way, though there are several good solution over the years.) 


Inevitably, in the early 19th century, this vocabulary was systematized -- more or less -- along the lines of philosophical languages: each syllable taken as first being given a category and then, within that, the second specifying a subject more narrowly.  And so on.  Certain simpler patterns were set aside for the crucial components: personal pronouns, "to be" and "to have", major prepositions and conjunctions.  There was also the heuristic devise that polar opposites were reversals of one another (which disrupted the philosophical pattern).  And there were other devices to help learning.  Oddly, given the musical foundation and that the creator was a music teacher, musical symbolism seems not to have entered vocabulary building at all: no special place is given to various chords or their permutations -- or to discords, for that matter.  Nor are the other multimedia potentials used - color wheels or finger symbolism, say.

Comes now the latest modern revision, Sarus, with the same basic scheme: seven syllable representable in a variety of ways.  Words are again built with these, but with some restrictions and alterations that make a bow to actual speaking conditions.  In compensation, Sarus allows words of up to six syllable, rather than only five, as in the original.  But still, there are over fifty thousand words available, as opposed to only about eleven thousand in the original.