Upper UI (Widgets)
There are a number of important tools at the top of the screen.
This is the Home button. Tap this to go back to the file picker screen. Your composition will be saved automatically.
This is the Tempo widget. Swipe left and right to make coarse adjustments to the tempo. Tap the Metronome button to enable audible ticks at each meter mark during playback.
You can also tap the widget to open a more fine-grained picker. Tap the title to save the new tempo and close the picker.
This is the Instrument widget. Swipe left and right to cycle between your different layers.
If you tap the Instrument widget, you'll open a panel where you can modify the properties of each layer. Layers can be switched by tapping the tabs at the top of the panel.
If you tap the button with the current layer's instrument, you can pick a new instrument for that layer. (Note that it's not currently possible to transform an instrument layer into a percussion layer or vice-versa.)
You can also add or erase layers in this panel.
This is the Meter widget. Swipe left and right to set the number of bars in each measure. (This affects note snapping — described below — and the metronome.)
You can tap the Meter widget to additionally set the emphasized beats in each measure. This only affects the sound of the metronome ticks.