  Recently, an approximate $SU(4)$ chiral spin-flavour symmetry was observed in
multiplet patterns of QCD meson correlation functions, in a temperature range
above the chiral crossover. This symmetry is larger than the chiral symmetry of
massless QCD, and can only arise effectively when colour-electric quark-gluon
interactions dynamically dominate the quantum effective action. At temperatures
about three times the crossover temperature, these patterns disappear again,
indicating the screening of colour-electric interactions, and the expected
chiral symmetry is recovered. In this contribution we collect independent
evidence for such an intermediate temperature range, based on screening masses
and the pion spectral function. Both kinds of observables behave
non-perturbatively in this window, with resonance-like peaks for the pion and
its first excitation disappearing gradually with temperature. Using symmetry
arguments and the known behaviour of screening masses at small densities, we
discuss how this chiral spin symmetric band continues into the QCD phase
diagram.
