Small songbird with short, fine bill. Breeding males have black crown and back, white underparts, black wings with bold white wing panels, and black tail with white tip. In nonbreeding plumage crown and back brown, with pale-edged feathers in dark upperwing. Female similar to nonbreeding male. Inhabits lightly wooded areas, especially eucalypt, foraging in pairs or small flocks in the mid- to upper story. Song is a loud, clear series of notes that descend and accelerate into a trill.