A suggestion from the Greek, Turkish and Klezmer Clarinet forum: the G clarinet was introduced from the West around 1830, and Turkish notation uses
the same transposition convention as the West does for that.
But. I just looked up Charles Fonton's book on Turkish music (published in 1767 in French; I have the 1987 Turkish translation) and the facsimile
scores reproduced in it use the same pitch range as modern Turkish notation. So while the adoption of the G clarinet may have reinforced the
practice, I don't think it can have started it. And it certainly predates Turkish nationalism by a very long way. |