  An approach to QCD vacuum as a medium describable in terms of statistical
ensemble of almost everywhere homogeneous Abelian (anti-)self-dual gluon fields
is reviewed. These fields play the role of the confining medium for color
charged fields as well as underline the mechanism of realization of chiral
$SU_{\mathrm L}(N_f)\times SU_{\mathrm R}(N_f)$ and $U_{\mathrm A}(1)$
symmetries. Hadronization formalism based on this ensemble leads to manifestly
defined quantum effective meson action. Strong, electromagnetic and weak
interactions of mesons are represented in the action in terms of nonlocal
$n$-point interaction vertices given by the quark-gluon loops averaged over the
background ensemble. Systematic results for the mass spectrum and decay
constants of radially excited light, heavy-light mesons and heavy quarkonia are
presented. Relationship of this approach to the results of functional
renormalization group and Dyson-Schwinger equations, and the picture of
harmonic confinement is briefly outlined.
