Where are the Trill effect buttons? Is there any reference?
The F1 to F4 keys on the PC keyboard functions as Trill buttons in IMPRESS mode. Pressing and releasing F1 and F2 keys while playing a note produces an upper or lower trill effect. Pressing F3 and F4 keys produces an automatic trill, while F5 produces a tremolo effect. The trill buttons are introduced in the Step 5 of the “How to Play” under Impress mode.