  The Ray-Singer isospectral theorem (1971) is applied to a general spectral
function for Laplacians of twisted p-forms (say) on homogeneous Clifford-Klein
factors of the three-sphere. The inducing formulae necessary to express any
spectral quantity for any twisting in terms of those for cyclic subgroups of
the tetrahedral, octahedral and icosahedral deck groups are detailed. Further,
Artin's theorem allows the McKay correspondence to be obtained. The isospectral
theorem is shown to yield a derivation of the Sunada construction which is
equivalent to the later one by Pesce.
