Trio Sonata No. 1 in E-flat major, BWV 525

The first of Bach's six organ trio sonatas, BWV 525 was composed in Leipzig around 1727 and is thought to have been written partly as practice material for Bach's eldest son Wilhelm Friedemann. Each of the three movements sets two independent melodic lines in the manuals against a walking bass on the pedals — demanding complete independence of both hands and feet and placing extraordinary coordination requirements on the performer. The trio sonata idiom, derived from chamber music, was entirely new to the organ when Bach adopted it, and the resulting works are among the most intellectually rigorous and expressively diverse in the solo organ canon. The opening Allegro moderato of BWV 525 balances Italianate melodic invention with Bach's characteristic contrapuntal density.