  A single master equation is given describing spin $s\le2$ test fields that
are gauge- and tetrad-invariant perturbations of the Kerr-Taub-NUT spacetime
representing a source with mass $M$, gravitomagnetic monopole moment $-\ell$
and gravitomagnetic dipole moment (angular momentum) per unit mass $a$. This
equation can be separated into its radial and angular parts. The behavior of
the radial functions at infinity and near the horizon is studied and used to
examine the influence of $\ell$ on the phenomenon of superradiance, while the
angular equation leads to spin-weighted spheroidal harmonic solutions
generalizing those of the Kerr spacetime. Finally the coupling between the spin
of the perturbing field and the gravitomagnetic monopole moment is discussed.
