I recall a short science fiction story about a revolution of musicians who play a sort of conical shaped harp. The ruler amputates their right arms to prevent them playing revolutionary songs, but they learn to play a new kind of one-handed trumpet instead and defeat the ruler. Does anyone know the title and author?
The Still, Small Voice of Trumpets by Lloyd Biggle Jr.
"Democracy imposed from without is the severest form of tyranny" runs the motto of the Interplanetery Relations Bureau, who's mission it is to bring democracy to all the worlds of the galaxy. So there secret agents work from within to bring about change. But on Kurr revolt is all but impossible. So Officer Forzon invokes the "Rule of One": one technological change per world. But making only the one change isn't as easy as it sounds.
One guess as to what that one-handed musical invention was...
A shorter novelette form was published in the April, 1961 edition of Analog Science Fact & Fiction, as The Still, Small Voice