Underground Sound of Lisbon (sometimes shortened to USL) is a collaboration between Portuguese house music producers Rui da Silva (then known as Doctor J) and DJ Vibe (real name Tó Pereira), who were active between 1993 and 2001.

The duo started working together in 1993 by founding Kaos Records, the first Portuguese electronic music label, with promoter António Cunha.

But the USL moniker prevailed, becoming much more internationally recognized after the track "So Get Up", a hard tribal anthem with spoken-word apocalyptic proclamations by Californian vocalist-lyricist Ithaka Darin Pappas[1] (more often known simply as Ithaka, but credited on that specific release as "Korvowrong"), received airplay in New York clubs at the hands of DJ Junior Vasquez, which led to a worldwide release at the Tribal America label.

After the release of their final album, Etnocity, the duo officially entered an indefinite hiatus, as both artists wanted to branch out into other fields and work with other producers.

In the US, on Twisted Records (U.S.), it was released as a maxi-single CD that featured the Portuguese sound mix, the a cappella, called here "Lula-pella" and its signature remix-version, 15 minutes and 10 seconds long, by American producer Johnny Vicious: "The Mushroom Head Mix".