The always essential Alex Ross decodes the mysterious presidential chord. It seems we were all wrong in assuming that Bush was simply being a jackass, cluelessly strumming a guitar while New Orleans descended into chaos.
It seems to be a strongly dissonant sonority consisting of the notes G, G#, A, B, C, and D . . . . Here he plays the pitch-class set named 6-Z11 in the Allen Forte system â€” a hauntingly ambiguous chord that brushes against the ghost of a now defunct tonality even as it stares ahead remorselessly into the chromatic future.