the Austrian musicologist Hartmut Krones has worked extensively on music and rhetoric and I would highly recommend his article in the music encyclopedia MGG "Musik und Rhetorik", although I'm afraid it is only available in German. There will be another special issue of the annual journal "Rhetorik" on music and rhetoric in 2016 (http://www.degruyter.com/view/j/rhet).
I work with rhetoric in the Brazilian colonial period music. My focus is currently the presence of European topic's under José Maurício Nunes Garcia music's. I worked also with the work of Marcos Portugal , which make available on ResearchGate .
OK, then if you accept the idea of tuning languages, maybe you might be interested in scordatura for violin music. Again, I don't know if scordatura is absolute, or not. There is an amusing solution to the problem of scordatura in which the alternate tuning is depicted on the musical staff as if the tuning had not changed. This means the violinist does not have to learn to read the tab. However, the effect is so confusing as to be absurd and this method has no practical use. The problem with scordatura is the play-by-number effect is diminished because it is so difficult to learn to write tablature.
On the violin it seems alternate tunings are not very useful but on guitar there are at least 10 very good tunings, and more that 100 guitar tunings have been reported. I don't think there are even 8 violin tunings.
Tablature, of course, dates to pre-1600s but has gone through many weird forms of notations. You have a system of reading, writing, and learning.