  I review applications of superconformal algebra. light-front holography, and
an extended form of conformal symmetry to hadron spectroscopy and dynamics. QCD
is not supersymmetrical in the traditional sense -- the QCD Lagrangian is based
on quark and gluonic fields -- not squarks nor gluinos. However, its hadronic
eigensolutions conform to a representation of superconformal algebra. and
provide a unified Regge spectroscopy of meson, baryon, and tetraquarks with a
universal Regge slope. The pion $q \bar q$ eigenstate is composite but yet has
zero mass for $m_q=0.$ Light-Front Holography also predicts the form of the
nonperturbative QCD running coupling in agreement with the effective charge
determined from measurements of the Bjorken sum rule. One also obtains viable
predictions for hadron dynamics such as spacelike and timelike hadronic form
factors, structure functions, distribution amplitudes, and transverse momentum
distributions. The combined approach of light-front holography and
superconformal algebra also provides insight into the origin of the QCD mass
scale and color confinement. A key tool is the dAFF principle which shows how a
mass scale can appear in the Hamiltonian and the equations of motion while
retaining the conformal symmetry of the action. When one applies the dAFF
procedure to chiral QCD, a mass scale $\kappa$ appears which determines the
hadron masses in the absence of the Higgs coupling. The result is an extended
conformal symmetry which has a conformally invariant action even though an
underlying mass scale appears in the Hamiltonian. Although conformal symmetry
is strongly broken by the heavy quark mass, the supersymmetric mechanism, which
transforms mesons to baryons (and baryons to tetraquarks), still holds and
gives remarkable mass degeneracies across the spectrum of light, heavy-light
and double-heavy hadrons.
