  Seigar, et al, have recently demonstrated a new, tight correlation between
galactic central supermassive black hole (BH) mass and the pitch angle of the
spiral arm in disc galaxies which they attribute to other indirect
correlations. They fit a double power law, governed by five parameters, to the
BH mass as a function of pitch. Noting the features of their fitted curve, we
show that a simple linear proportion of the BH mass to the cotangent of the
pitch angle can obtain the same fit, within error. Such a direct, elegant fit
may help shed light on the nature of the correlation.
