In EarSketch, what is the 'timeline' used for?

The timeline in EarSketch serves as a visual interface that allows users to arrange and manipulate audio clips effectively. It provides a structured way to organize different audio segments, making it easy to see how clips fit together in a musical composition. Users can drag and drop audio elements onto the timeline, adjust their lengths, and reposition them for optimal sequencing. This visual representation is crucial for both beginners and experienced users as it simplifies the process of editing, layering, and timing audio clips, enabling them to create complex musical pieces with ease.

The other options refer to different functionalities that do not accurately describe the primary role of the timeline. While audio files are certainly part of the project, they are not "stored" in the timeline but rather arranged and manipulated using it. Summarizing musical notes and configuring audio settings involve separate processes that are not directly related to the purpose of the timeline.