You may find this variant is better at keeping the text in the upper-left corner of the screen regardless of the width of your window:
def addInstructions(pos, msg):
return OnscreenText(text=msg, style=1, fg=(1,1,1,1),
pos=(0, pos), parent = base.a2dTopLeft,
align=TextNode.ALeft, scale = .05)
There is also a base.a2dTopRight, a2dBottomLeft, a2dBottomRight, a2dTopCenter, and so on.
David