I just got from a friend detailed information about another surrogate language system, this one from Euskalerria (the Basque Country). It is extinct as media, but still used as musical instrument.
Txalaparta: the talking drum from Euskalerria
by David Casacuberta
Not so long ago, in Euskalerria, the Basque Country (a nation that now is part of the Spanish State), the Txalaparta was used a communication medium.
The Txalaparta (the "tx" is pronnounced like a "sh", but stronger, with the tip of the tongue in the upper teeth) is a percussion instrument, made with a set of big wooden planks, usualy leaning over logs. The txalaparta is then hit with 50 cm. sticks called "makilak". Like a xylophone, according to where you hit, you get a different tone and sound.
Like the Canary silbo, described in another dead media working note (Note 25.8), this is also a surrogate language, that uses tones to codify sentences. It was developed for the same reasons: the existence of ravines and cliffs that are so common in the Atlantic part of the Basque Country. People living in "caserios" (the typical country houses in the basque country, usually quite far one from the other) used the drums to communicate with the neighbours, by means of txalapartas put on the top of some hills.
However, let us mention that the possible meanings that could be sent with the txalaparta are more limited than the ones aviable in the Canary silbo.
Now, due to the advancing of telephones and other media, txalaparta is extinct as a medium, but is still used as a musical instrument. It is normally played by two people, but sometimes they can be even four. The sound is really beautiful and impressive, and you can hear a txalaparta in almost every traditional "fiesta" in Euskalerria.
If you have a good record store around and are interested to hear a txapalarta, there are some UNESCO records of it, and there is also a rock band from Euskalerria that recorded a txalaparta in one of their songs. The band is called "Hertzainak," the LP "Onena" and the song, "564."
However, the common lore says that the best txapalarta players (in Euskera they are called txalapartak) in the Basque Country are the Artza brothers. If you have the luck to find a record by them, go for it!
David Casacuberta (firstname.lastname@example.org)