Recently an approximate SU(4) chiral spin-flavour symmetry was discovered in
multiplet patterns of QCD meson correlation functions, in a temperature range above
the chiral crossover. This symmetry is larger than the full chiral symmetry
of QCD with massless u,d-quarks. It can only arise effectively
when color-electric quark gluon interactions dominate the effective Dirac action
of QCD, which suggests that quarks remain bound in such a regime.
At temperatures about two to three times the crossover temperature, this
pattern disappears again, and the usual chiral symmetry is recovered.
We present additional evidence for this phenomenon based on meson screening
masses, and discuss how this chiral spin symmetric band continues into
the QCD phase diagram.