public Keystroke(
	Tone tone,
	double duration,
	byte velocity = 64
)

Public Sub New ( 
	tone As Tone,
	duration As Double,
	Optional velocity As Byte = 64
)

public:
Keystroke(
	Tone tone, 
	double duration, 
	unsigned char velocity = 64
)

new : 
        tone : Tone * 
        duration : float * 
        ?velocity : byte 
(* Defaults:
        let _velocity = defaultArg velocity 64
*)
-> Keystroke