  We study Rabi oscillations between the bands of an arbitrary biased
superlattice in a tight-binding model. We reduce the problem to an equation of
Whittaker--Hill type and, in absence of any known solutions in closed form,
discuss different approximations to describe the oscillations between the Bloch
bands. We identify regimes of weak and strong inter-band coupling and compare
predictions for these Rabi oscillations to numerical results.
