diff --git a/js/components/Visualizer.js b/js/components/Visualizer.js
index f49011f3..9ad4801a 100644
--- a/js/components/Visualizer.js
+++ b/js/components/Visualizer.js
@@ -99,6 +99,50 @@ function preRenderBar(barWidth, height, colors, renderHeight) {
   return barCanvas;
 }
 
+function paintOscilloscopeFrame({
+  canvasCtx,
+  colors,
+  bufferLength,
+  width,
+  height,
+  dataArray
+}) {
+  canvasCtx.lineWidth = PIXEL_DENSITY;
+
+  // Just use one of the viscolors for now
+  canvasCtx.strokeStyle = colors[18];
+
+  // Since dataArray has more values than we have pixels to display, we
+  // have to average several dataArray values per pixel. We call these
+  // groups slices.
+  //
+  // We use the  2x scale here since we only want to plot values for
+  // "real" pixels.
+  const sliceWidth = Math.floor(bufferLength / width) * PIXEL_DENSITY;
+
+  const h = height;
+
+  canvasCtx.beginPath();
+
+  // Iterate over the width of the canvas in "real" pixels.
+  for (let j = 0; j <= this._renderWidth(); j++) {
+    const amplitude = sliceAverage(dataArray, sliceWidth, j);
+    const percentAmplitude = amplitude / 255; // dataArray gives us bytes
+    const y = (1 - percentAmplitude) * h; // flip y
+    const x = j * PIXEL_DENSITY;
+
+    // Canvas coordinates are in the middle of the pixel by default.
+    // When we want to draw pixel perfect lines, we will need to
+    // account for that here
+    if (x === 0) {
+      canvasCtx.moveTo(x, y);
+    } else {
+      canvasCtx.lineTo(x, y);
+    }
+  }
+  canvasCtx.stroke();
+}
+
 class Visualizer extends React.Component {
   componentDidMount() {
     this.barPeaks = new Array(NUM_BARS).fill(0);
@@ -219,54 +263,26 @@ class Visualizer extends React.Component {
 
   _paintOscilloscopeFrame() {
     this.props.analyser.getByteTimeDomainData(this.dataArray);
-
-    this.canvasCtx.lineWidth = PIXEL_DENSITY;
-
-    // Just use one of the viscolors for now
-    this.canvasCtx.strokeStyle = this.props.colors[18];
-
-    // Since dataArray has more values than we have pixels to display, we
-    // have to average several dataArray values per pixel. We call these
-    // groups slices.
-    //
-    // We use the  2x scale here since we only want to plot values for
-    // "real" pixels.
-    const sliceWidth =
-      Math.floor(this.bufferLength / this._width()) * PIXEL_DENSITY;
-
-    const h = this._height();
-
-    this.canvasCtx.beginPath();
-
-    // Iterate over the width of the canvas in "real" pixels.
-    for (let j = 0; j <= this._renderWidth(); j++) {
-      const amplitude = sliceAverage(this.dataArray, sliceWidth, j);
-      const percentAmplitude = amplitude / 255; // dataArray gives us bytes
-      const y = (1 - percentAmplitude) * h; // flip y
-      const x = j * PIXEL_DENSITY;
-
-      // Canvas coordinates are in the middle of the pixel by default.
-      // When we want to draw pixel perfect lines, we will need to
-      // account for that here
-      if (x === 0) {
-        this.canvasCtx.moveTo(x, y);
-      } else {
-        this.canvasCtx.lineTo(x, y);
-      }
-    }
-    this.canvasCtx.stroke();
+    paintOscilloscopeFrame({
+      canvasCtx: this.canvasCtx,
+      colors: this.props.colors,
+      bufferLength: this.bufferLength,
+      width: this._width(),
+      height: this._height(),
+      dataArray: this.dataArray
+    });
   }
 
-  _printBar(x, height, peakHeight) {
-    height = Math.ceil(height) * PIXEL_DENSITY;
+  _printBar(x, barHeight, peakHeight) {
+    barHeight = Math.ceil(barHeight) * PIXEL_DENSITY;
     peakHeight = Math.ceil(peakHeight) * PIXEL_DENSITY;
-    if (height > 0 || peakHeight > 0) {
-      const y = this._height() - height;
+    if (barHeight > 0 || peakHeight > 0) {
+      const y = this._height() - barHeight;
       const ctx = this.canvasCtx;
       // Draw the gradient
       const b = this._barWidth();
-      if (height > 0) {
-        ctx.drawImage(this.barCanvas, 0, y, b, height, x, y, b, height);
+      if (barHeight > 0) {
+        ctx.drawImage(this.barCanvas, 0, y, b, barHeight, x, y, b, barHeight);
       }
 
       // Draw the gray peak line