Readers' Poll: The Top 10 Metal Bands of All Time

Tool aren't the most prolific metal band out there – they've released only four albums since their formation in 1990. By comparison's sake, Black Sabbath released their fourth album about three years into their career. But despite their minimal output and complete lack of hit singles, Tool have built up one of the biggest cult audiences in all of metal. The band broke big in 1993, right at the height of the alternative music movement. They didn't sound anything like Pearl Jam or Smashing Pumpkins, but they still gained a big following with the release of their debut LP, Undertow, particularly after they toured with Lollapalooza that summer. MTV even put their video for "Sober" into semi-regular rotation. Since then, their audience has grown, despite long gaps between projects. Their last album hit in 2006, but they have reportedly been working on a new album for the past couple of years.