Collaborative communication system with voice and touch-based interface for content discovery

A user interface (UI) is provided on a client device to a user. The UI includes a concept bar and a content window. The concept bar includes a plurality of concept tabs associated with concepts currently relevant to a collaborative communication session involving the user and other participants. The concept tabs are configured to enable interaction with the concept tabs by the user. The content window is presented separately from the concept bar, and includes content relevant to the collaborative communication session based on the concept tabs presented by the concept bar. The content presented by the content window is modified in response to interaction by the user with the concept tabs.