The purpose of this study was to examine and describe children's music improvisations and the interactions that transpired within their four-person groups during regular weekly music classes as they planned and performed music improvisations in response to three different prompts: a poem, a painting, and a musical composition. Participants were two classes of fifth-grade children at the elementary school where the researcher was the general music teacher. Sixteen children in four focus groups were chosen for closer observation and a series of interviews. Data were gathered over a 12-week period, utilizing audio- and video-recorded observations, daily field notes, and interviews following students' viewing of their own performances on video. The findings of this study demonstrate that (a) all children utilized a similar planning process, and social roles and relationships were often correlated to musical roles and relationships; (b) children's music products differed based on the nature of the prompt, and children viewed prompts along a continuum of providing freedom of expression; and (c) children evidenced three specific strategies and expressed three valued considerations for planning and evaluating improvisation performances. (Contains 1 table and 7 figures.)