  We use representation theory to construct spaces of matrices of constant
rank. These spaces are parametrized by the natural representation of the
general linear group or the symplectic group. We present variants of this idea,
with more complicated representations, and others with the orthogonal group.
Our spaces of matrices correspond to vector bundles which are homogeneous but
sometimes admit deformations to non-homogeneous vector bundles, showing that
these spaces of matrices sometimes admit large families of deformations.
