The autograph score of Lalo's much-played concerto is lost; the only remaining sources are the 1st edition score/parts as well as the autograph piano reduction by Lalo. Hugh Macdonald, the highly acclaimed editor of French music, has discovered that Lalo's piano reduction was used as a working score by Lalo himself. He continued to make alterations to the work in the reduction even after the work was officially published. These changes provide for many corrections in the solo part as we know it.