Chicago Underground Duo is an experimental jazz duo consisting of cornetist and keyboard player Rob Mazurek and percussionist Chad Taylor. They formed in 1997, having both been members of Chicago Underground Orchestra and recorded their first album in 1998. Mazurek also appeared on Tortoise's TNT in 1998. The following year, the pair expanded to become Chicago Underground Trio after adding Noel Kupersmith on bass and laptops to the lineup, though they still record as a duo, and even as a quartet (with guitarist Jeff Parker) on 2001's Chicago Underground Quartet. Kupersmith was replaced by bassist Jason Amejian on the "live" album Chronicle in 2006. They have released numerous recordings on the Thrill Jockey label including their latest 2006 release In Praise of Shadows.