dropping a fourier series

dx = N[Pi/30];
Manipulate[
 Module[{n, ydrop},
  n = 1 + Floor[t];
  ydrop = 4 - 3.5 (0.5 + 0.5 Tanh[5 (Mod[t, 1] - 0.5)]);
  If[t >= 10, ydrop = 10];
  Graphics[{
    EdgeForm[Black], FaceForm[],
    Table[
     Module[{y = 0.5 + Sum[1/i (1 + 0.5 Sin[i x]), {i, 1, 2 n, 2}],
       y2},
      y2 = Max[y, ydrop] + 1/(2 n + 1) (1 + 0.5 Sin[(2 n + 1) x]);
      {
       FaceForm[
        ColorData["RedBlueTones"][
         0.5 + 0.4 Sum[4/(Pi i) (Sin[i x]), {i, 1, 2 n, 2}]]],
       Rectangle[{x, 0}, {x + dx, y}],
       FaceForm[ColorData["RedBlueTones"][0.5 + 0.5 Sin[(2 n + 1) x]]],
       Rectangle[{x, Max[y, ydrop] }, {x + dx, y2}]
       }
      ], {x, -2 Pi, 2 Pi, dx}]

    }, PlotRange -> {{-2 Pi, 2 Pi}, {0, 5}}, AspectRatio -> 0.61,
   ImageSize -> 500, ImagePadding -> 2]
  ],
 {t, 0, 10}
 ]