Half Blood Blues by Esi Edugyan

The aftermath of the fall of Paris, 1940. Hieronymus Falk, a rising star on the cabaret scene, is arrested in a cafe and never heard from again. He is twenty years old. A German citizen. And he is black.

Fifty years later, Sid, Hiero's bandmate and the only witness that day, is going back to Berlin. Persuaded by his old friend Chip, Sid discovers there's more to the journey than he thought when Chip shares a mysterious letter, bringing to the surface secrets buried since Hiero's fate was settled.

In Half Blood Blues, Esi Edugyan weaves the horror of betrayal, the burden of loyalty and the possibility that, if you don't tell your story, someone else might tell it for you. And they just might tell it wrong ...- Goodreads