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He also wants to transpose the entire piece up a bit, so he double-taps to bring up the menu. He chooses 'edit'->'select all', and then drags a note up to transpose the whole piece.
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Analysis
Learnability
The app is intended to be as easy to learn and use as possible.
Efficiency
As necessitated by screen size constraints, some features are hidden in menus, which makes it somewhat less efficient to use them. Other efficiency issues will hopefully come up in user testing.