t.A.T.u. is a pop duo which formed in Moscow, Russia in 1999. The group consisted of singers Lena Katina and Julia Volkova. The discography of t.A.T.u., contains 9 albums (three Russian and three English studio albums, 2 remix albums and one compilation album) plus 22 singles. Together over 20 million copies of t.A.T.u. releases was sold. In 2000, the duo's first single - "Я сошла с ума", was released and quickly became popular on Russian radio stations.