Wilhelm Friedemann Bach, the oldest Bach son, displayed a distinctive creative individualism in his output. His sonatas for solo keyboard instrument (harpsichord or fortepiano), which rank amongst his major works, shaped the development of the then-young genre and his posthumous reputation. With their often-capricious melodies and harmony, improvisatory features, but also the combination of galant and contrapuntal stylistic ideals, the sonatas are a real discovery. All the sonatas for solo keyboard instrument plus the Concerto in F major for two harpsichords are published in five volumes as separate editions from the Wilhelm Friedemann Bach Complete Edition.