Chiral symmetry and the properties of hadrons in the generalized Nambu-Jona-Lasinio model

Various aspects of the generalized Nambu-Jona-Lasinio model of QCD in four dimensions are reviewed. The properties of mesonic excitations are discussed in detail, with special attention on the chiral pion. Spontaneous chiral symmetry breaking in a vacuum and effective chiral symmetry restoration in the spectrum of highly excited mesons and baryons are described microscopically.