Johann Sebastian Bach · 1708 · Tonal Music
Core Mechanism
Systematic constraint migration — a fixed structural element progressively transfers across registers while fragmenting, forcing the compositional system to solve the same problem under increasingly restrictive conditions until the constraint itself must be abandoned to continue.
Kernel Engagement
Works within the kernel’s native ground; the structural gap is present but never encountered.
Evidence
The eight-measure ground bass operates as a mobile constraint that migrates through registers while fragmenting, generating cascading structural consequences Bach didn't independently choose. The systematic constraint migration makes the fifth's operation visible as the audience can perceive the ground bass doing its structural work across 20 variations.
Territory
The work uses fifths-based harmonic organization as primary language throughout. The ground bass, all variations, and the fugue operate within functional harmony with clear tonic-dominant relationships and fifth-generated motion.
Constitutive depth
The ground bass migration generates endogenous constraints — when the bass fragments in variations 16-20, the system reaches maximum constraint density and forces the shift to fugue to continue intensifying. Bach didn't choose these cascading consequences; they emerged from the constraint migration mechanism doing what it does.
Legibility
The ground bass is explicitly stated and its systematic migration through registers is structurally audible to any musically literate listener. The mechanism is foregrounded as compositional content — the audience perceives the constraint doing its work, not just experiencing its effects.