  AdS/QCD, the correspondence between theories in a modified five-dimensional
anti-de Sitter space and confining field theories in physical space-time,
provides a remarkable semiclassical model for hadron physics. Light-front
holography allows hadronic amplitudes in the AdS fifth dimension to be mapped
to frame-independent light-front wavefunctions of hadrons in physical
space-time, thus providing a relativistic description of hadrons at the
amplitude level. We identify the AdS coordinate $z$ with an invariant
light-front coordinate $\zeta$ which separates the dynamics of quark and gluon
binding from the kinematics of constituent spin and internal orbital angular
momentum. The result is a single-variable light-front Schr\"odinger equation
with a confining potential which determines the eigenspectrum and the
light-front wavefunctions of hadrons for general spin and orbital angular
momentum. The mapping of electromagnetic and gravitational form factors in AdS
space to their corresponding expressions in light-front theory confirms this
correspondence. Some novel features of QCD are discussed, including the
consequences of confinement for quark and gluon condensates. The distinction
between static structure functions, such as the probability distributions
computed from the square of the light-front wavefunctions, versus dynamical
structure functions which include the effects of rescattering, is emphasized. A
new method for computing the hadronization of quark and gluon jets at the
amplitude level, an event amplitude generator, is outlined.
