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- Since users found the top menu bar confusing, we removed one of the buttons and replaced the "Main Menu" button with "Save" and "Exit" buttons.
- We decided that editing individual notes would be done through a modal overlay, so that users could use more of the limited screen space to swipe and drag.
- Audio editors commonly support arbitrarily many tracks, which can be moved around, created, and deleted. Our prototype originally used a scrolling list of tracks, but we replaced that with a layers metaphor where there are exactly four tracks, and they're overlaid on top of each other on the screen.
- We added small time markings at the top of the editing screen, as suggested by users