`this.$playPauseButton.text(...)` is called in four different locations. This one is the only one which updates the value of `playing` but all of them manually change the text of `this.$playPauseButton` directly with very similar logic by accessing `playingText` directly. We could refactor this out to a method called `updatePlayPauseButton` and replace this line with the following:

    ++playing;
    this.updatePlayPauseButton();

Other calls to `this.updatePlayPauseButton();` wouldn't need to increment `playing`.

The method would be as such:

    updatePlayPauseButton: function () {
        this.$playPauseButton.text(playingText[playing % 2]);
    }

Since `playingText` would no longer be required in different locations at this point the method could easily operate on a ternary statement.