Both of these bassists possess tremendous technical skills and they both know exactly when to use them. They are modern metal royalty; Chancellor in the mainstream and Marston in the deep, deep underground.

Tool parted ways with original bassist Paul D'Amour in 1995, but even though D'Amour was brilliant while working with Adam Jones on the strings, Tool's music evolved significantly after Justin Chancellor joined. Since the release of 'Ænima' in 1996, Tool have become much more complex, delving into odder time signatures and psychedelic tearing of life's very fabric. Chancellor is more than just an exceptional player, he's also proven to be a motivating force within the group to create new material.

Colin Marston is a true player's player and he's one of the few individuals who can legitimately play ANYTHING on his bass and Warr guitar. As a bassist, Marston has given a great deal to prog metal trio Dysrhythmia and most recently to Gorguts on the enlightening 'Colored Sands.' When experiencing any of Marston's projects live, your eyes can't help but lock onto the musician in disbelief of his blistering skills.

Justin Chancellor or Colin Marston? Vote for your favorite bassist in the poll below! Voting for this round closes on Sunday, Sept. 29 at 11:59PM ET. Fans can vote once per hour, so keep coming back to make sure that your favorite metal musician wins!