Toccata and Fugue in F major, BWV 540

The toccata starts with a large linear canon (imitation theme, one hand imitating the other) over a pedal point in F major. It is then followed by a pedal solo vamping material from the canon. The canon is reiterated with some variations in the dominant in C major. This time the hands are switched, and the left hand leads the right. This is again followed by a long pedal solo. The two large canon flourishes cover 108 measures of the composition. The pedal solos cover 60 measures. The concerto movement exhibits a seven-part structure. The canons and pedal solos effect the departure from the home key of F to the dominant C, and the entire rest of the movement, with its concertante 3-part imitation and striking "proto-waltzes", constitute the harmonic return. This formal pattern is unique within Bach's œuvre.