But the moment conservatives do this, everyone goes nuts – it's hypocrisy of the highest order.

There are signs that the age of petroleum has passed its zenith. Adjusted for inflation, a barrel of crude oil now sells for three times its long-run average. The large western oil companies, which cartellised the industry for much of the 20th century, are now selling more oil than they find, and are thus in the throes of liquidation.

With the song 'This Christmas' I wanted to do something that was kind of different. I mean, Donny Hathaway is an amazing artist. So I wanted to bring my flavor to the song so when people over the age of 45 or 50 hear it they'll be like 'OK, he did his thing with that record.' It's like I can appeal to everybody and not just a younger demographic.