Thelonious Monk, considered one of the greatest Jazz pianists of all time, recorded Underground in '67-'68. It's the last recording with the Thelonious Monk Quartet (Larry Gales on bass, Charlie Rouse on tenor sax, and Ben Riley on drums) and one of the last album he made for Columbia.

What makes Underground special is that unlike his other Columbia recordings, four out of the seven songs were newly composed and recorded. The album cover depicts Monk as a member of the French Resistance and is meant as an homage to Pannonica "Nica" de Koenigswarter. She was a member of the aristocratic Rothschild family and became a patron of leading jazz musicians, hosting jam sessions, driving them to gigs and sometimes even help out with paying the rent. In 1969 the cover won a Grammy for Best Recording Package.
Underground is available as a limited edition of 2000 individually numbered copies on orange vinyl and comes in a deluxe, heavy duty sleeve.