The purpose of this study was to observe, analyze, and document the range of young children's interactions with sound-producing objects in order to better understand the nature of such interactions. Of particular interest was whether theories of cognitive play, social play, object play, and existing research on musical play could guide concurrently the interpretation of children's interactions with these objects and whether the interactions were consistent with these theories. Two groups of participants, nine 3-year-old children and seven 4-year-old children, played with sound-producing objects for approximately 15 min once a week for 12 weeks. Participants interacted with the objects in rich and varied ways, including explorations of the objects' sound-producing capabilities and other physical attributes, nonmusical and musical functional and pretend play episodes, and construction behaviors. Movement and singing often were layered upon the children's interactions with the objects. Musical functional play was the most frequently observed behavior across both ages of participants. The children were more likely to engage in solitary/parallel behaviors than group interactions, and group interactions were more common among the 4-year-old children than the 3-year-olds. All behaviors that were anticipated via the conceptual framework were observed, with the exception of group nonmusic exploration.