System of a Down, also known by the acronym SOAD, is an American rock band from Southern California and formed in 1994. The above is the System of A Down logo seen on the cover artwork of their second album, Toxicity. The overall wavy look of the logo resembles the famous Hollywood sign. You can recreate the logo with a font named Hollywood Hills, download it for free here.
This logo features the underlined band name in script lettering, as seen from their third album, Steal This Album!. It is probably handwritten and not a font.