Bach, Chaconne from Partita for Violin No. 2, BWV 1004, arranged by Brahms for left hand piano:  The Chaconne is the fifth movement of Bach’s Partita in D Minor for Unaccompanied Violin, written between 1717-1723 (ages 32-38), while Bach was in the service of Prince Leopold in Cöthen.  Joshua Bell has said that the Chaconne is “not just one of the greatest pieces of music ever written, but one of the greatest achievements of any man in history.  It’s a spiritually powerful piece, emotionally powerful, structurally perfect.”  Brahms knew and loved the music of Bach at a time that it was mainly of historical interest.  His respect for Bach’s Chaconne was reverential: “The Chaconne is in my opinion one of the most wonderful and incomprehensible pieces of music.  Using the technique adapted to a small instrument, [Bach] writes a whole world of the deepest thoughts and most powerful feelings.”  In 1877 (age 44), when his close friend Clara Schumann injured her right hand, Brahms arranged Bach’s Chaconne for left-hand piano.  Brahms told Clara Schumann that, only by arranging the work this way could he understand the technical difficulties faced by a violin soloist.