Passacaglia and Fugue in C minor, BWV582

The piece opens with a bare, eight-measure bass line, played alone in the pedals: this is the "ground bass" that will repeat throughout the passacaglia, a form built on obsessive repetition. Once you have that line in your ear, listen for it returning again and again, sometimes buried in the bass, sometimes climbing into the upper voices, while the music above it grows more elaborate, from simple chords to running scales to dense, syncopated textures. There are no breaks between variations; the piece accumulates in one continuous span, building steadily in volume and complexity toward a climax of full organ sound before subsiding.

After the passacaglia's final variation, the fugue begins, on a new subject that actually contains the old bass line's opening notes tucked inside it, a subtle link between the two halves. A fugue is a piece in which one melodic idea enters in one voice, then is imitated in turn by others, weaving in and out; here Bach adds a second countersubject that recurs alongside it. The fugue builds in the same accumulating way as the passacaglia, adding voices and harmonic tension, until it arrives at a final, thickly chorded close.

In orchestral versions, such as Ottorino Respighi's, the same shape holds, but the color changes with each variation, from strings alone to woodwind solos to full brass, letting the ear track the form through shifting instrumental families rather than organ stops.

Bach likely composed this work in Weimar, sometime in the 1710s, though the exact date is not documented; it stands as one of the largest and most ambitious organ works of the whole Baroque era. It was almost certainly written for his own use as a virtuoso organist, at a time when he held posts as court organist. The passacaglia form, built on a repeating bass line, was unusual to expand to this length and scale, and the work has long been treated as a benchmark for organists' technique and stamina. In the twentieth century its reputation grew beyond the organ loft: Ottorino Respighi orchestrated it in 1930, and Leopold Stokowski made his own arrangement as well, bringing the piece into the symphonic repertoire and introducing it to listeners who might never hear a pipe organ in concert.