West End Blues

Louis Armstrong · 1928 · Music

Core Mechanism

Systematic rotation of a single variable (timbre) while holding all other structural parameters constant, making the isolated variable perceptible as the primary carrier of formal development.

Kernel Engagement

Works within the kernel’s native ground; the structural gap is present but never encountered.

Evidence

The work maintains a consistent 32-bar AABA harmonic grid across five choruses with standard blues-jazz chord progressions, using the fifth as invisible infrastructure for timbral variation rather than foregrounding fifth relationships as content.

Territory

The harmonic organization uses standard blues-jazz progressions built on fifth-generated functional harmony, with blue notes representing 7th harmonic inflection within diatonic territory rather than departure from fifth-based logic.

Constitutive depth

The fifth constitutes the harmonic framework but generates no endogenous constraints—Armstrong chose the timbral rotation system independently of any demands the kernel made. The work operates within fifth-generated harmony without the kernel forcing structural consequences.

Legibility

The fifth operates as naturalized infrastructure—audiences experience the harmonic progression as familiar background supporting the timbral foreground. The kernel's operation is invisible without analytical attention to the underlying chord changes.