Song singing is a specific socio-cultural action that encompasses linguistic and musical components, The conventions for organizing these components are variable, The lyrics and melody are coordinated in order to produce a coherent unit with linguistic and musical elements organized in parallel hierarchies. Songs that are actually invented reveal the producer's ability to comprehend implicitly and apply cultural conventions on making a song. Moreover, consecutively invented songs show how creatively, flexibly, and differentiatedly these conventions are used. A nine-year-old girl was shown a picture and asked to invent songs. She produced eight songs which were analyzed with a microgenetic method. The songs' organization of pitch and time were analyzed with a computer-aided method. The organization of the lyrics, the pattern of pitches, and the timing are represented graphically. The detailed description permits observation of the singer's rules that have been applied for creating a coherent linguistic and musical product. The girl repeatedly used linguistic and melodic structures that are being elaborated and recombined throughout the process. She accompanied her products with various types of self-corrective comments and statements that revealed her mental conception of how she intended to monitor her performance to create a song. Without being asked, she commented on her products whether she succeeded or not. Apart from traditional song structures, we identified various other sources that guided the girl's invented performances: The picture shown to stimulate the inventions. the songs previously taught, and the conventions on making verse songs.