Vocalization is the most common, primitive and universal musical expression. All essential parameters are present: pitch and timing of vowels, and loudness. Yet, the analysis of vocal musical production is an intricate issue. This paper has three aims: First, a new methodology for analyzing and representing children's singing is introduced. This method is based on acoustic analyses and in addition on a new graphical visualization. The latter serves to represent the acoustic measures as given by the analyses. The advantage is to have pitch and time adequately depicted. Second, this method is demonstrated with a case study. It is an excerpt of a large developmental study on how children adapt to our vocal culture (music, language) while creating new songs. Finally, it is shown how descriptive data resulting from a microgenetic study provide insights into how a child organizes the multiple parameters (syllables, its pitches and timing) into coherent units. Patterns of this creative process are becoming visible. It is claimed a) that analyses of such creative processes are a solid basis for a better understanding – in other words: a theory - of music development; b) that such processes are core issues of progress in musical development.