With Mathematica 10, it's possible to draw the semicircle distribution of R. Wigner:
data = RandomVariate[WignerSemicircleDistribution[1, 3], 10^4]; Show[ Histogram[data, 20, "PDF"], Plot[PDF[WignerSemicircleDistribution[1, 3], x], {x, -2, 4}, PlotStyle -> Thick]] 
My question is: how can I make an animated version of Wigner semicircle distribution as shown below?


data := RandomVariate[WignerSemicircleDistribution[0, 1], 10^2]; Dynamic[ Show[ Histogram[data, 10, "PDF"], Plot[PDF[WignerSemicircleDistribution[0, 1], x], {x, -2, 4}, PlotStyle -> Thick] , PlotRange -> 2] , UpdateInterval -> .2]$\endgroup$