Prism (album)
Prism is the fourth studio album by American pop singer-songwriter Katy Perry. It was going to be much darker than her earlier material, though it became an upbeat, dance-inspired album. The songs "Roar" and "Birthday" are on the album.  The album debuted at number one on the US Billboard 200 with first-week sales of 286,000 copies.  Prism features the singles "Roar", "Unconditionally", "Dark Horse" featuring American rapper Juicy J, "Birthday", and "This Is How We Do".  The first and third singles both reached number one on the Billboard Hot 100, while the second and fourth singles became top-twenty hits in the US.  All of the singles have been certified platinum or higher in the US, with "Roar" and "Dark Horse" each being certified Diamond.