  In this paper we provide a physical picture for the QCD phase transition in
terms of qualitative changes in the spectral functions. Our approach takes into
account the crossover nature of this transition and counts for the observed
strong correlation seen in higher order susceptibilities. We demonstrate that
the hadron resonance gas, which alone describes the thermodynamics at
temperatures $T<T_c$, will appreciably contribute to the total pressure until
$T\leq 3T_c$. In this intermediate regime the QCD matter consists of strongly
correlated excitations, interpretable as either hadrons or partons. As hadronic
spectral peaks gradually vanish, the partonic excitations start to form a
stand-alone quasiparticle gas. The conventional picture of a quark gluon plasma
emerges only at $T\geq 3T_c$.
