We describe the integral cohomology of the generalized Kummer fourfold, giving an explicit basis, using Hilbert scheme cohomology and tools developed by Hassett and Tschinkel. Then, we apply our results to an irreducible holomorphic symplectic variety with singularities, obtained by a partial resolution of the generalized Kummer fourfold quotiented by a symplectic involution. We calculate the Beauville-Bogomolov form of this new variety, presenting the first example of such a form that is odd.