I am interested in brain functions that can be characterized by a computational goal encompassing sensory inputs and motor outputs. My favorite examples are vocal production and vocal learning, which I study in songbirds using reductionist experimental and theoretical approaches. We have started to investigate the structure of the nervous system in birds using a combination of electron and light microscopy, termed correlative array tomography (CAT); we perform electrophysiological recordings to read out the neural code in singing birds; and we design behavioral experiments to study vocal communication and social learning in bird groups. Currently we are trying to identify the simplest possible mechanistic equations to describe song learning trajectories.