The evolution of a galaxy is driven by the state of its interstellar
medium. Dense molecular gas serves as the site for the formation of
young massive stars, which in turn heat the gas and may drive outflows
of material. Understanding the evolution of galaxies, therefore,
requires quantitative measurements of the interstellar medium in wide
range of galaxies from puny dwarf galaxies to mighty LIRGs. In this
talk, I argue that developing wide-field, moderately high resolution,
spectral line capabilities are key to this understanding using recent
GBT 4mm observations of dense molecular gas as an example. These, and
other observations, are already uncovering differences in the
relationship of dense molecular gas to star formation in other nearby
galaxies.