This is J.G. Graun's only solo sonata for viola da gamba and basso continuo. It exists in two variants: the composer's autograph and a transcription by L.C. Hesse. Graun's original is quite demanding for the performer, and we believe that Hesse adapted and simplified it for the Prussian crown prince Friedrich Wilhelm. Whereas Hesse's version has long been known as an anonymous work, Graun's original has been found in the Archive of the Berlin Sing-Akademie, which has only become available in recent years. Since both versions are authentic examples of the early classical galant style, we are publishing them side by side in a single performing edition, with an extensive introduction by Michael OÆLoghlin.