KxNa1-xNbO3 (KNN)-based solid solutions are promising lead-free piezoelectrics for ceramic actuators. In this system, the long-range order of octahedral rotations and ferroelectric displacements coexists with significant local disorder of both types of displacements. Industrially relevant KNN compositions are those around the morphotropic phase boundary (MPB) at x=0.5 that separates polar orthorhombic (O) and monoclinic (M) structures. On heating, both phases transform to a tetragonal (T) polymorph. Enhanced piezoelectric properties are observed at this polymorphic phase boundary (PPB), but the exact role of this PPB in the enhancement of a piezoelectric response remains unclear. The goal of the proposed experiments is to provide critical neutron total scattering data to determine the relationships between the local and average atomic displacements across the MPB and PPB.