Among the weakly interacting probes, the most frequently used is the electromagnetic one. There are two classes of processes that have been studied: One mediated by the $normal$ component of the chiral Lagrangian and the other by the $anomalous$ component.

The lepton pair production via virtual photon V\^\*l\^+ l\^-\[V\] where $V=\rho, \ \omega$ and $l=e, \ \mu$ is governed by the $normal$ component of the HLS$_1$ Lagrangian. Most of the past efforts to unravel chiral dynamics of hadrons in medium were directed to this process. Several heavy-ion experiments have been dedicated at CERN-SPS to expose $directly$ in-medium properties of the $\rho$ meson in hot and dense medium. The most recent and comprehensive review on the current situation regarding this class of experiments can be found in the articles by van Hees and Rapp [@rapp]. We will argue below that within the HLS/VM theory that we believe is suited to the problem, the lepton pairs in heavy-ion processes are [*neither efficient nor specific*]{} for exposing in-medium properties of the $\rho$ meson bearing on chiral symmetry, in particular, on the “dropping mass" effect.

The other class involves processes that are mediated by the $anomalous$ Wess-Zumino term in chiral Lagrangians. The process studied 