The extension of classical discriminant analysis techniques in multivariate analysis to time series data is a problem of practical interest. Discrimination between different classes of multivariate locally stationary processes, which constitute a class of non-stationary processes, can be characterized by differing covariance or time varying spectral structures. For discrimination between the multivariate non-Gaussian locally stationary processes, Kullback-Leibler discrimination information measure has been developed. In this paper, asymptotic error rates and limiting distributions are given for a generalized time varying spectral disparity measure that includes foregoing criteria as special case. It is well known that the log-likelihood ratio based on observed stretch gives optimal classification. It is shown that the discriminant criterion based on such generalized disparity measure is Gaussian optimal. A non-Gaussian optimal discriminant criterion is also proposed in view of the LAN theorem.