In this talk, I will survey several recent resutls related to the genesis of rhythms in the nervous system, particularly in the so-called gamma range. I will first describe some mechanisms and aspects of rhythms which depend on the interactions between excitatory and inhibitory neurons. Next I will explore what happens when there are changes in the circuitry and some ways in which the rhythms can break down. I will connect this breakdown in rhythms to symptomology in schizophrenia. Finally, if time permits, I will suggest a new role for oscillations in working memory.