Burr was undoubtedly one of the best drummers in metal. You can't listen to songs like Innocent Exile, Phantom of the Opera and the iconic Run to the Hills without being blown away by his adept rhythm.
The former drummer struggled with MS for years and in 2002 the band set up the Clive Burr MS Trust to raise funds for treatment and lodgings. The boys from the band and Burr enjoyed a great friendship and they're clearly all saddened by his passing.
So if you're a fan of metal, hell, if you're a fan of music at all, throw on Iron Maiden, Killers or Number of the Beast and bask in Burr's unholy awesome tub-thumping. He will be missed.