  Mesons as bound states of quark and anti-quark in the framework of a
relativistic potential model are studied. Interaction of constituents in bound
state is described by the Lorentz-scalar QCD inspired funnel-type potential
with the coordinate dependent strong coupling, {\alpha}S(r). Lagrangian
relativistic mechanics is used to derive the main dynamic two particle equation
of motion. On this basis, relativistic two body wave equation is derived.
Solution of the equation for the system in the form of a standing wave is
obtained. Two exact asymptotic expressions for the meson squared mass are
obtained and used to derive the meson universal mass formula. Light and heavy
meson mass spectra are calculated.
