  Using the black string between two branes as a model of a brane-world black
hole, we compute the gravity wave perturbations and identify the features
arising from the additional polarizations of the graviton. The standard
four-dimensional gravitational wave signal acquires late-time oscillations due
to massive modes of the graviton. The Fourier transform of these oscillations
shows a series of spikes associated with the masses of the Kaluza-Klein modes,
providing in principle a spectroscopic signature of extra dimensions.
