As half a million trumpet fans descend on the tiny village of Guča, Serbia, for the world’s largest trumpet competition, historical and ethnic tensions still smolder beneath the surface of the small Balkan country. Brasslands follows three musical groups who seek the crown. The reigning champions represent generations of acclaimed Serbian musicians; a Romani group struggles against racism for the right to make a living from their music; and an unlikely American band must win over an audience that still resents America's role in the NATO bombings of two decades ago.