  Extreme and very-near-extreme spin J Kerr black holes have been conjectured
to be holographically dual to two-dimensional (2D) conformal field theories
(CFTs) with left and right central charges c_L=c_R=12J. In this paper it is
observed that the 2D conformal symmetry of the scalar wave equation at low
frequencies persists for generic non-extreme values of the mass M.
Interestingly, this conformal symmetry is not derived from a conformal symmetry
of the spacetime geometry except in the extreme limit. The periodic
identification of the azimuthal angle is shown to correspond to a spontaneous
breaking of the conformal symmetry by left and right temperatures (T_L,T_R).
The well-known low-frequency scalar-Kerr scattering amplitudes coincide with
correlators of a 2D CFT at these temperatures. Moreover the CFT microstate
degeneracy inferred from the Cardy formula agrees exactly with the
Bekenstein-Hawking area law for all M and J. These observations provide
evidence for the conjecture that the Kerr black hole is dual to a c_L=c_R=12J
2D CFT at temperatures (T_L,T_R) for every value of M and J.
