Moravian-born composer and pianist Gideon Klein was just 22 when he was deported from Prague to the Terezín (Theresienstadt) ghetto. Working alongside fellow-internees, some ranked amongst Czechoslovakia’s finest musicians, Klein has been almost totally referenced by his imprisonment. It is true that he made a significant impact on the ghetto’s cultural activities, and positioning Klein in this context is perhaps inevitable and understandable as an awareness of the extent of artistic expression, some of it as forms of resistance, on the part of Jewish musicians in Nazi-occupied Europe continues to expand. Yet it is also somewhat simplistic when evaluating the complex circumstances that took place in Terezín. Informed by research into archival materials especially in the Czech Republic, this chapter traces Klein’s development before his incarceration and places special focus on the String Trio and possible references in the musical narrative of that particular work to the composer’s Jewish heritage. It also raises the important question as to whether we can, or even should, now define Klein’s music, and that of similar composers, beyond the discourse of creativity under German occupation in general, and during the Holocaust in particular.