Abstract: Instant messenger conversations (chats) with multiple participants are one way of fostering creativity, either in brainstorming sessions or, as micro-creativity, in computer-supported collaborative learning (CSCL) sessions. A model used for analysing such chats is based on the remark that they are often composed of several intertwining threads behaving like voices in polyphonic jazz music. This model was used in the design and implementation of several NLP platforms, such as PolyCAFe and ReaderBench, which were used for analysing CSCL chat sessions and generating feedback for learners and teachers. The polyphonic model was also used for analysing face-to-face learning sessions, brainstorming sessions, and discussion forums. It was also the basis for generating sonifications of conversations.