About Bill Kaulitz
Bill Kaulitz, also known as Billy for his solo project, is a German singer and songwriter. He is best known for his work as the lead vocalist of the pop rock band Tokio Hotel. On stage, Kaulitz was noted and well known for his energetic style and harmonizing with the fans (he would frequently let the audience sing verses instead of him). In 2006, Kaulitz voiced the role of Arthur in the first part of the German version of the film Arthur and the Invisibles. Their first single from Schrei was "Durch den Monsun" ("Through the Monsoon"), which reached #1 in Germany within a month of its release.
Biography source: Wikipedia. The profile adds birthday-specific historical context from the Celebs Birthday Today editorial database.