One of the best ways to expand your knowledge of the guitar’s fingerboard is to play music written for, or originally played by, other instruments. Bluegrass guitarists learn fiddle tunes, jazz guitarists learn saxophone and trumpet solos, and classical guitarists arrange lute, piano, and even orchestral music. Bach’s music has been a touchstone for all sorts of musicians looking to explore new harmonic and melodic ideas, with the Six Sonatas and Partitas for solo violin particularly valuable to stringed instrument players. Opening a volume of these influential pieces can be daunting. But if you are patient and methodical, and take a few measures at a time, Bach’s solo violin music can provide some reachable challenges for the fingers of both hands.