We examined auditory perception in Williams syndrome by investigating strategies used in organizing sound patterns into coherent units. In Experiment 1, we investigated the streaming of sound sequences into perceptual units, on the basis of pitch cues, in a group of children and adults with Williams syndrome compared to typical controls. We showed that individuals with Williams syndrome were sensitive to the same pitch cues as typical children and adults when streaming these patterns. In Experiment 2, we evaluated differences in reliance on pitch and contour cues in unfamiliar melody perception in a group of adults with Williams syndrome relative to typical control children and adults. Unlike controls who demonstrated greater proficiency when contour cues were available, adults with Williams syndrome showed no such advantage.