J.S. Bach: Sonatas For Solo Violin BWV 1001-1006, played by Sigiswald Kuijken; Deutsche Harmonia Mundi 1C 157 (1999603).
There are many other Deutsche Harmonia Mundi (and U.S.A. HM) recordings of Baroque repertoire, all featuring excellent "historically-informed" performances, and in superior recorded sound. They range from solo instrumental works (harpsichord, organ, cello, etc.), small ensemble works, and full orchestra pieces.