  The effective QCD-interaction as obtained from the front form Hamiltonian by
DLCQ is Fourier transformed on the Retarded Schr\"odinger Equation for to
describe the constituents of physical mesons. The crucial point is the use of a
running coupling constant $\alpha_s(Q^2)$, in a manner similar but not equal to
the one of Richardson in the equal usual-time quantization. Fixing the running
coupling constant at the Z mass, the only parameters are the flavor masses.
Without the top quark one needs thus 5 parameters to calculate the physical
masses of 30 pseudoscalar and vector mesons, consistently within the same
model. Applying variational methods to a caricature of the model, the biggest
technical challenge is the solution of a cubic algebraic equation. -- In view
of an oversimplified model and a very simple technology, the agreement with the
empirical data is much too good.
