The twins are active since ca. 1983, and produce hip hop music since 1992. Their first instrumental was on the album Alte Schule ("Old school"), the first songs that featured the twins rapping were "HipHop und Rap" ("HipHop and Rap") and "Allein zu zweit" ("Alone Together") and were released in 1995 on the album The Sound of MZEE. They are considered pioneers of German hip hop and their productions were ahead of their time and a formative influence. Although they have only released one rap album, they are well respected in Germany because of their lyrics critical of the music business, staying true to the original elements of the artform, spoken in distinctive Heidelberg accent.
They have worked with many German artists, and have also collaborated with artists such as GZA of the Wu-Tang Clan, Prodigal Sunn of Sunz of Man and the Arsonists.