  We describe how to construct chiral fermion mass terms using Dirac-Kahler
(DK) spinors. Classical massive DK spinors are shown to be equivalent to four
generations of Dirac spinors with equal mass coupled to a background U(2,2)
gauge field. Quantization breaks U(2,2) to U(2)xU(2), lifts mass spectrum
degeneracy, and generates a non-trivial mass mixing matrix.
