Dance-forms for Bach had much symbolism outside their measure or meter; the Aria ‘Erbarme Dich’ from the St.Matthew Passion for example is based on the pastoral Siciliano, the final chorus from the St. John Passion on the Sarabande. The Siciliano from the Flute Sonata No 2 in E flat major ( BWV 1031) is a softly lilting and deeply meditative pastorale. Its inspiration seems entirely that of the master, though other movements from the same Sonata have been alternatively attributed.