  In this talk we discuss the microscopic limit of QCD at nonzero chemical
potential. In this domain, where the QCD partition function is under complete
analytical control, we uncover an entirely new link between the spectral
density of the Dirac operator and the chiral condensate: violent complex
oscillations on the microscopic scale give rise to the discontinuity of the
chiral condensate at zero quark mass. We first establish this relation exactly
within a random matrix framework and then analyze the importance of the
individual modes by Fourier analysis.
