The "Metal Gear Solid Main Theme" is a musical piece synonymous with the Metal Gear series. It is made up of two musical themes. The first "motif" was written by TAPPY, who was requested to write the theme by Hideo Kojima, and appeared in Metal Gear Solid. It was later remixed by Harry Gregson-Williams for Metal Gear Solid 2: Sons of Liberty, and the melody was partially used in other Metal Gear Solid games (such as Metal Gear Solid: The Twin Snakes and Metal Gear Solid 3: Snake Eater). The second theme appears later in Metal Gear Solid 3 and Metal Gear Solid 4: Guns of the Patriots.