SINCE THE IRON CURTAIN FIRST started to tear in the early '80s, music lovers in the West have been exposed to a number of previously unknown composers whose reputations were obscured by the rigid Soviet system, among them Edison Denisov, Sofia Gubaidulina and Alfred Shnitke. Now comes a man who may well be the most important composer to emerge from the old Soviet Union since Dmitri Shostakovich: Giya Kancheli, 59, whose dolorous yet spiritually radiant music gives eloquent voice to the ongoing tragedy of his native Georgia.
"Music is a kind of self-reflection," says the staunchly nationalistic composer. "I don't try...