  We calculate the scalar-gravitational quasi-normal modes of equal angular
momenta Myers-Perry black holes in odd dimensions. We find a new bar-mode
(non-axisymmetric) classical instability for $D \ge 7$. These black holes were
previously found to be unstable to axisymmetric perturbations for spins very
near extremality. The bar-mode instability we find sets in at much slower
spins, and is therefore the dominant instability of these black holes. This
instability has important consequences for the phase diagram of black holes in
higher dimensions.
