  Precision measurements of jet substructure are used as a probe of fundamental
QCD processes. The primary Lund jet plane density is a two-dimensional visual
representation of the radiation off the primary emitter within the jet that can
be used to isolate different regions of the QCD phase space. A new measurement
of the primary Lund plane density for inclusive charged-particle jets in the
transverse momentum range of 20 and 120 GeV/$c$ in pp collisions at $\sqrt{s} =
$ 13 TeV with the ALICE detector will be presented. This is the first
measurement of the Lund plane density in an intermediate jet $p_{\rm T}$ range
where hadronization and underlying event effects play a dominant role. The
projections of the Lund plane density onto the splitting scale $k_{\rm T}$ and
splitting angle $\Delta{R}$ axis are shown, highlighting the
perturbative/non-perturbative and wide/narrow angle regions of the splitting
phase space. Through a 3D unfolding procedure, the Lund plane density is
corrected for detector effects which allows for quantitative comparisons to MC
generators to provide insight into how well generators describe different
features of the parton shower and hadronization.
