Robert Derhak, also known simply as Rob, is the bass guitar player and a founding member of the American jam band moe.

Derhak's earliest known time performing as a member of a band was on Halloween 1989, playing at a party with guitarist Chuck Garvey and a drummer named Ray Schwartz.

Moe returned to the stage at the Capitol Theatre in Port Chester NY on February 2, 2018 and have since resumed a regular touring schedule.

In 2003 Derhak teamed up with several members of Assembly of Dust, including Andy Herrick (drums), Adam Terrell (guitar) and Nate Wilson (keyboards).

The group called themselves "Swampdonkey" and performed also exclusively in the Northeastern United States, playing several shows at the Alehouse in Portland, Maine, at moe.down IV, and finally at the Revolution Hall in Troy, New York.