This chapter explores the differences between group interactions that are relatively improvised and those that are relatively fixed. It elaborates the frameworks by exploring the degree of improvisationality of group creativity. Cultural rituals typically include both musical and verbal interaction, and the degree of improvisation in each mode tends to develop in parallel. In American music, the genre of jazz improvisation is the most receptive to novelty. Saussure's view of historical linguistics implied that ordinary language use tends toward the improvisation end of continuum, since genre changes tend to be incremental and short-lived. Ritualized musical performance genres demonstrate almost all of the characteristics found in ritualized verbal performance genres; improvised musical genres demonstrate almost all of the characteristics found in improvised verbal genres. An exception is the low audience involvement of free jazz. A focus on group creativity allows to integrate analyses of both musical and verbal performance.