int numCurves = 50;

float tt = 50; // change with time

void setup() {
  //size(800, 600);
  fullScreen();
  noFill();
  strokeWeight(2);
  stroke(255);
  noCursor();
}

void draw() {
  background(0);
  float ty = 100; // change with vertical position
  for (int i = 0; i < numCurves; i++) {
    float tx = 0; // change with horizontal position
    beginShape();
    float alpha = map(i, 0, numCurves, 50, 255);
    stroke(255, alpha);
    for (int x = 0; x < width -1; x+=10) {
      float y = i*20 + noise(tx, ty, tt) * 400 - 50;
      vertex(x, y);
      tx += 0.02;
    }
    endShape();
    ty += 0.05;
  }
  tt += 0.001;
}