  We compute an the genus 1 correction to free energy of Hermitian two-matrix
model in terms of theta-functions associated to spectral curve arising in large
N limit. We discuss the relationship of this expression to isomonodromic
tau-function, Bergmann tau-function on Hurwitz spaces, G-function of Frobenius
manifolds and determinant of Laplacian in a singular metric over spectral
curve.
