GR translation: wearied blown sheets of tropic string cadences

[Mike Jing]

P171.18-24   . . .—here what’s this, an actual, slick and crimson,
hot, squeak-stockinged slavegirl “gam” yes right among these
winter-pale clinical halls, with the distant gramophone playing rumba
music, basses, woodblocks, wearied blown sheets of tropic string
cadences audible as everyone dances back there on the uncarpeted
floors, and the old Palladian shell, conch of a thousand rooms, gives,
resonates, shifting stresses along walls and joists . . .

what are these "wearied blown sheets"?  Is it sheet music in the wind,
or something else?