Those four lads from Birmingham probably had no idea what they were starting when they entered the studio in 1969 to record their first album. Tony Iommi’s dark, gloomy and slow distorted riffs created the heavy metal guitar with only two valid fingers on the neck of his trusty Gibson SG. Every single metal band owes a huge debt to Black Sabbath, especially the albums featuring singer / howler Ozzy Osbourne. Forty years later, the gloominess of these first records has not aged at all.