  We present results of a supernova light-curve population synthesis,
predicting the range of possible supernova lightcurves arising from a
population of progenitor stars that include interacting binary systems. We show
that the known diversity of supernova lightcurves can be interpreted as arising
from binary interactions. Given detailed models of the progenitor stars, we are
able to the determine what parameters within these stars determine the shape of
their supernova lightcurve. The primary factors are the mass of supernova
ejecta and the mass of hydrogen in the final progenitor. We find that there is
a continuum of light-curve behaviour from type IIP, IIL to IIb supernovae
related to the range of hydrogen and ejecta masses. Most type IIb supernovae
arise from a relatively narrow range of initial masses from 10 to 15
M$_{\odot}$. We also find a few distinct lightcurves that are the result of
stellar mergers.
