Chiral Disorder in QCD

Using the Gell{endash}Mann{endash}Oakes{endash}Renner relation and semiclassical arguments, we show that the bulk quark spectrum in QCD exhibits a variety of regimes including the ergodic one described by random matrix theory. We analyze the quark spectral form factor in the diffusive and ballistic regime. We suggest that a class of chiral transitions in QCD is possibly of the metal-insulator type, with a universal spectral statistics at the mobility edge. {copyright} {ital 1998} {ital The American Physical Society}