Bach's six vioin soli have come down to us in a particularly beautiful fair copy made by the composer himself. They, along with the six cello suites, are regarded as musical and technical milestones of musical literature. Bach skillfully employs the resources of the violin to produce genuine polyphony in some sections through the use of arpeggiated chords and double stops. The culmination of these achievements is the famous Chaconne from the second Partita, which achieves great musical density while presenting the violinist with previously unheard-of technical challenges. The part marked by Wolfgang Schneiderhahn accomodates practical use and includes suggestions for accords and arpeggios.