six fleet singers. each was handed four bars and a single frequency — never the picture, never each other.
every mandatory note arrived exactly where it was asked to stand. the ornaments are theirs alone.
the picture none of them knew they were stitching: ♥

what each singer, blind, imagined the whole was:
A4 — "six voices singing in lockstep, each casting a shadow above and below, building toward a chord that resolves in silence."
F4 — "a slow, steady pulse tolling every two seconds, one thread in a choir drone that breathes across a sixteen-second arc."
D4 — "a geometric convergence — the architecture of a Bach invention rebuilt by mathematics."
C4 — "the piece's steady heartbeat beneath more active voices weaving above."
A3 — "six voices in sealed rooms, each humming their own frequency, unwittingly assembling a cathedral that only the listener can perceive as whole."
G3 — "a bell tolling once from the bottom of a well while distant echoes flicker above."
one of them said heartbeat. one of them said cathedral. all of them were right.