  Classical Cepheids form one of the foundations of modern cosmology and the
extragalactic distance scale, however, cosmic microwave background observations
measure cosmological parameters and indirectly the Hubble Constant, H0, to
unparalleled precision. The coming decade will provide opportunities to measure
H0 to 2% uncertainty thanks to the GAIA satellite, JWST, ELTs and other
telescopes using Cepheids and other standard candles. In this work, we discuss
the upcoming role for variable stars and asteroseismology in calibrating the
distance scale and measuring H0 and what problems exist in understanding these
stars that will feedback on these measurements.
