Smooth

Depending on your musical persuasion this little bit of tomfoolery will either leave you with a big smile on your face, or you'll be writing a stiffly worded letter to the CEO of Youtube complaining most bitterly that YouTube wasn't made for this sort of thing - "Stick to skateboarding cats and montages of Donald Trump offending all and sundry."
Personally, I adore it. Although I don't have a Metallic bone in my body, the very idea that someone (Andy Rehfeldt) could see beyond Enter Sandman and turn it into a smooth jazz classic is genius. Pure genius. Let's clap it in.

Metallica - Enter Sandman (Smooth Jazz version)