On-Screen Keyboard
Keyboard
The on-screen Keyboard can be used to play notes and also visually displays notes that are played on a connected physical keyboard.
Toggle Keyboard View
Use the Toggle Keyboard View button to flip the on-screen Keyboard from 24-key mode to 88-key mode.
Mod-Wheel
The on-screen Mod-Wheel can be used to control the low-pass filter programmed on some Sounds. If you have connected a physical keyboard with a Mod-Wheel, the on-screen Mod-Wheel will mirror the physical Mod-Wheel as it is moved.
The Sunday Keys App will automatically recognize modulation MIDI data from a Primary Controller if it is sending on CC1, modulation. If your controller’s Mod-Wheel is not automatically recognized and mirrored by the on-screen Mod-Wheel, you can easily connect them via MIDI Learn.
Sustain
The on-screen Sustain button can be used to latch Sustain behavior on and off, useful if you’re using only the on-screen keyboard for preparation on the go. If you have connected a physical keyboard with a sustain pedal, the on-screen Sustain button will also act as an indicator when that physical sustain pedal is engaged.
Layer Ranges
You will see a Sound’s Layer Range represented by a colored bar just above the on-screen Keyboard. Sounds come programmed with a default Layer Range that can be adjusted. To adjust the Layer Range, tap the Layer Range button 
to show the Layer Range Adjust view. You can set/adjust a Layer’s Lowest and Highest notes in two ways:
- By tapping the square
representing the lowest or highest note for the layer range on your keyboard, then playing the desired lowest or highest note. - By tapping and dragging either end of a Sounds’ Layer Range up or down as desired
To exit the Layer Range visual, tap the Layer Range button or tap anywhere outside of the Layer area.