"One" is a song by heavy metal band Metallica. The song is released as the fourth single and fourth track of their fourth album …And Justice for All. "One" was also the band's first Top 40 hit single, peaking at #35 on the Billboard Hot 100.
"One" was written in November 1987 by Metallica's principal composers — rhythm guitarist/vocalist James Hetfield and drummer Lars Ulrich. The song was released in 1989 as the second single taken from the album (the first being "Harvester of Sorrow" in the U.S and "...And Justice for All" in Europe