How can I dynamically change the appearance of b? Strangely it works for the Enabled state but not for the Appearance.
Thanks.
Manipulate[
bAppearance = If[a > 1, "Open", "Closed"];
bEnabled = If[a > 2, False, True];
Plot[Sin[a x + b],
{x, 0, 6}], {a, 1, 4}, {b, 0, 10, Appearance -> Dynamic@bAppearance}]

