  For the original hybrid inflation model, we calculate the power spectrum of
curvature perturbations generated during the waterfall, taking into account the
contribution of entropic modes. We study the regime where the potential is very
flat, and in which inflation continues for more than about 60 e-folds. Results
show oscillations in the scalar power spectrum, qualitatively similar to that
of a single field axion monodromy potential; however no feature is displayed in
the tensor power spectrum. Directions to develop a template for this power
spectrum are also discussed.
