Stone Temple Pilots released their fourth studio album, No. 4, on October 26, 1999. The title refers to the band's album count, though it was initially considered to be called The Chinese Album.
The album was recorded in Los Angeles with producer Brendan O'Brien, who had previously worked with the band on their previous album, Tiny Music... Songs from the Vatican Gift Shop. Recording faced internal tensions due to vocalist Scott Weiland's addiction issues.
Despite mixed initial reviews, No. 4 peaked at number 6 on the Billboard 200 and was certified platinum by the RIAA in 2000. Singles like Sour Girl and Down achieved success on rock radio.