SYNOPSIS. This paper reviews song recognition in two congeneric species of sparrow the swamp sparrow (Melospiza georgiana) and song sparrow (Melospiza melodia). Data from psychophysical studies of hearing, tutoring experiments with young birds, and field playback studies with adult birds are considered together in order to gain insight into the mechanisms of species recognition through song development. In aggregate, the evidence suggests a multi-stage process of song development consisting of an early perceptual preference for learning conspecific song, a sensorimotor phase of song development during which vocal output matches an auditory memory as if through trial and error, and a final phase of full song which functions in territorial defense and mate attraction.