The album "WHO ARE YOU?" consists of 12 songs, recorded between 1999 and 2000 at the Moscow recording studio "Ton-Atelier No. 1" in the Ostankino telecenter. The recording of the album featured rappers Sheff, Legalize, Tima, and Tommy, as well as R&B performer Marusya and rock band "Mad Dog." The producers of the album were Alexander Tolmatsky and Vlad "Chef" Valov.
The music for the album was created by Shooroop and DJ LA, with the assistance of bassist and guitarist Mr. Bruce, DJ DJ Tonik (scratch on the song "Friday"), and rock band "Mad Dog" ("Tears"). All the lyrics for the album were written by Sheff, except for the songs "Hope for Tomorrow" (Sheff and Legalize), "Tears" ("Mad Dog"), "We Rest" (Sheff and Tommy), and "Friday" (Legalize).

Music videos were released for the tracks "Friday," "Tears," "Hope for Tomorrow," "Who Are You?," "Party," and "My Blood, Blood," three of which became laureates in the "Hit Parade-20" nomination at the first "Muz-TV" award ceremony. On September 7, 2000, Detsl and his producer "Chef" received the MTV Video Music Awards in the "MTV Russia Viewer's Choice" category for the music video for the song "Party."
The phrase from the album's title song "What have you done for hip-hop in your years?" became a motto for the next few years for hip-hop in Russia, and the album itself "WHO ARE YOU?" became a huge commercial success, selling more than a million copies. Critics from the Rap.ru portal called it the best rap album of 2000.
The album was a landmark event in the history of Russian hip-hop culture. It's the debut studio album of one of the most significant rappers in Russia, whose name has become legendary.