  We calculate the spectral function of light quark flavours in 2+1 flavour
vacuum QCD in the isospin-symmetric approximation. We employ spectral
Dyson-Schwinger equations and compute the non-perturbative quark propagator
directly in real-time, using recent spectral reconstruction results from
Gaussian process regression of gluon propagator data in 2+1 flavour lattice
QCD. Our results feature a pole-like peak structure at time-like momenta larger
than the propagator's gapping scale as well as a negative scattering continuum,
which we exploit assuming an analytic pole-tail split during the iterative
solution. The computation is augmented with a general discussion of the impact
of the quark-gluon vertex and the gluon propagator on the analytic structure of
the quark propagator. In particular, we investigate under which conditions the
quark propagator shows unphysical complex poles. Our results offer a wide range
of applications, encompassing the ab-initio calculation of transport as well as
resonance properties in QCD.
