Johann Sebastian Bach's Sonatas and Partitas for the Violin contains 3 partitas and 6 sonatas, all of which are excellent sources of musical material for lessons, developing sight-reading, or actually using on gigs when you need something classy.
You'll be hard-pressed to find music that develops a hands-on understanding of Western theory and chordal structures better than Bach, and it also teaches percussionists how to deal with music not idiomatically written for their own instruments - like the marimba.
Difficulty: Medium to Advanced
