  The sunspot penumbra is a transition zone between the strong vertical
magnetic field area (sunspot umbra) and the quiet Sun. The penumbra has a fine
filamentary structure that is characterized by magnetic field lines inclined
toward the surface. Numerical simulations of solar convection in inclined
magnetic field regions have provided an explanation of the filamentary
structure and the Evershed outflow in the penumbra. In this paper, we use
radiative MHD simulations to investigate the influence of the magnetic field
inclination on the power spectrum of vertical velocity oscillations. The
results reveal a strong shift of the resonance mode peaks to higher frequencies
in the case of a highly inclined magnetic field. The frequency shift for the
inclined field is significantly greater than that in vertical field regions of
similar strength. This is consistent with the behavior of fast MHD waves.
