Ronnie James Dio: The man who gave us the devil hornsOne of the great voices in metal has been stilled. Singer Ronnie James Dio, known for both his pioneering work in Black Sabbath and as a solo artist, died Sunday after a year-long bout with stomach cancer. He was 67.Although small in size, the vocalist was a giant in headbanging circles, taking over the reins in Black Sabbath from Ozzy Osbourne in 1980 and in so doing creating one of the hallmark albums of the genre, Heaven and Hell.The memorials for Dio are coming in furiously, but many have overlooked one of his most influential innovations: the devil horns.This iconic hand gesture - created by extending the index and fifth fingers - is as much a part of heavy metal as black T-shirts and squealing guitar solos. As Dio explained in Sam Dunn and Scot Macfadyen's 2005 documentary, Metal: A Headbanger's Journey, the sign was actually inspired by his superstitious grandmother. Back in the old country - i.e. Italy - she would flash the sign on sidewalks at people she thought were giving her the evil eye. The hand gesture was her method of warding off ominous spirits. Check out the above video for a more elaborate explanation.