How to bring the beautiful cover artwork to the front (wallpaper)

In the iPhone Music player you only ever see your beautiful cover artwork in square format on about half of the screen.

When you you start up SmartPlaylist you can tap "⌥" (Options) and select "➜ Now Playing" ...

 ... to jump  directly to the song which is now playing on the iPhone:

Here, you simply double-tap on the artwork to enlarge it to full screen:

With one finger you can move the artwork left or right until you get the desired frame. Now you press the home button and the on/off button on top at the same time to take a picture of what you see on the screen (you will get a white flash when this happens).
Then you go to the iPhone settings and select "Brightness & Wallpaper". You will find your full screen artwork picture in your Camera Roll.

So, with just a few taps you get a wallpaper from the artwork in your music library.