Tanja Siebert played her first concert as a jazz singer in the duo with wonderful guitarist Eric St. Laurent in 1998. Appearances in various jazz clubs in Berlin followed with Eric but also other musicians over the next two years. At that time she had started already a classical vocal training with Bernhard Raddatz, has sung Puccini, Verdi, Brahms, Schubert, but her heart is beating for the jazz. Since then she has improved her skills with different teachers. In 2001 she has founded the Tanja Siebert Quartet. It was always her dream to make music together with a piano trio.

In August 1998, Tanja Siebert gave up the study of German and North American studies and through an internship she came to Jazz Radio Berlin, where she has worked six years as a freelancer. Then she worked free five years for Radio Paradiso as a presenter. Currently, she works as a freelance as a speaker or presenter at events, lecturer in jazz singing at the jazz school in Berlin and of course singer.