Black is the most metal colour (silver at two, red at three, purple at four… again, don’t write in), so that’s a pretty good start. Then there’s Sirius – first, it sounds like ‘Serious Black’, which could be the name of a paint colour Dulux keep in a special cupboard because it’s too powerful. Then there’s the meaning of Sirius – it’s a star 8.6 light years away (metal) also known as the Dog Star (metal). Dogstar was also a band featuring Keanu Reeves on bass (metal) who played show with both Rancid (punk) and Weezer (a hard band to categorise but one that are very much on Harry Potter’s boat spectacles-wise). Plus he’s played by Gary Oldman, who won an Oscar for playing Winston Churchill, whose speeches are beloved of Iron Maiden. He pent a bunch of time in prison (metal), survived a few duels (metal) and has a good scruffy-suit-long-hair-tidy-beard thing going on (metal).