Johann Sebastian Bach’s Passacaglia and Fugue in C Minor, BWV 582, stands as one of the organ repertoire’s most formidable constructs, a work whose inexorable logic and subterranean power render it uniquely suited to the vigil of All Hallows’ Eve. Composed during Bach’s early Weimar years, it begins with a four-bar ostinato in the pedals, a descending chromatic line that functions less as theme than as gravitational force, pulling twenty variations into its orbit. Each variation tightens the coil: harmonies darken, rhythms fracture, and the manuals erupt in virtuosic filigree, until the architecture threatens to collapse under its own mass.

The fugue that follows is no mere appendage but the passacaglia’s apotheosis. The same bass line re-emerges, now as fugal subject, subjected to stretti, inversions, and a final cataclysmic convergence of voices. In Reitze Smits’s performance on the historic Müller organ of Haarlem’s St. Bavo, the effect is visceral: the instrument’s 1738 reeds and principals lend a raw, almost corporeal edge to the sound, the building itself seeming to exhale as pipes shudder like ribs around a hollow heart.

Beneath the mathematical rigor lies an almost Gothic sensibility. The passacaglia’s ground evokes the tolling of a death knell across fog-bound cloisters; the fugue’s mounting dissonance conjures spectral assemblies in candlelit vaults. Yet Bach never stoops to programmatic illustration. The terror is abstract, born of proportion and pressure, the same implacable order that governs both cosmos and crypt.

Listen in dim light, preferably through headphones that preserve the instrument’s subterranean growl. Let the ostinato anchor you as the variations ascend, then surrender when the fugue unleashes its final, heaven-storming cadence. On Halloween, no other Baroque work so perfectly marries mortal dread with divine architecture.