The past few years have seen the emergence of new observational approaches to the study of pulsating stars. Massive photometric surveys are discovering new variables by the tens of thousands. For example, the number of Cepheids and RR Lyrae has increased manifold over the past two years – many of these new distant pulsating stars have now better light curves than their well-known nearby counterparts. The new observational breakthrough has opened many theoretical issues. Some of these can be tackled with the set of new opacities (from Lawrence Livermore and from the Opacity Project), others seem to require new theoretical insights.