Hadronic excitations and chiral symmetry in nuclear systems

This presentation discusses recent developments in our understanding of low-mass quark-antiquark excitations, both of the condensed QCD vacuum and in a nuclear medium. We focus primarily on two selected topics: the thermodynamics of the chiral condensate and in-medium s-wave interactions of pions with emphasis on the recently observed deeply bound pionic atom states, and on pion electroproduction in nuclei.