Field stars cover the whole range of chemical abundance, and contain information about the early history of the Galaxy, its age and its chemistry. Our perception of the chronology is heavily dependent on theoretical stellar models. Globular clusters in the halo, and stars actually within the galactic bulge, are too faint to be observed directly. However, there are local counterparts presently in the solar vicinity that can be observed, and which are tracers of the early chemical history of the Galaxy. Groups of stars falling within a narrow range of metallicity define narrow evolutionary tracks on the H-R diagram. Members of each group were presumably formed contemporaneously, and from seismic studies of the stars near the main-sequence turnoff and in the subgiant branch, a chronology can thereby be established. A major improvement to the chronology of the spherical halo, the inner halo, the bulge and the old disk is expected from the seismic constraints imposed on the helium abundances, the sizes of the convective cores and the amount of diffusion inferred particularly in metal-poor stars. Ultimately the uncertainty in the age of the Galaxy could be reduced by a factor 3 to 5, leading to a reduction in the uncertainty, by a factor of the same order, in the value of the Hubble constant H0. Indeed, there may be no other way to constrain H0 so tightly.
Galactic bulge stars exhibit a broad range of metallicity, up to 5 or 6 times solar. Disk globular clusters located at the edge of the bulge also have very high metallicity. According to the present models these stars seem to be older than the classical globulars. However, on dynamical grounds, the bulge stars look younger. This leads to a real difficulty in determining the sequence of events in the early evolution of the Galaxy. The question is: was it the stars near the galactic centre that were formed first, or was it the globular clusters in the halo? It is highly probable that the resolution of this issue will require a more reliable treatment of convection and element segregation in metal-rich stars. Sub-metal-rich stars in the field have been demonstrated to be the local counterpart of the bulge population; their seismic analysis will certainly clarify this important chronological problem.