When the cord is bowed against the string, it creates a unique timbre which has been described as "sounds of an infinite resonance that have no equivalent among other instruments".
To Rădulescu, the striking image of the grand piano on its side presented the instrument "in a new light; it now resembles a religious object – a Byzantine icon".
Rădulescu is reported to have used a variety of materials to both bow and pluck the piano strings, including fishing line as well as gold coins.
In works with multiple sound icons, Rădulescu would weave "spider webs of nylon threads of different thickness in between the pianos".
[3] In each piece, Rădulescu would work out a very precise tuning for the sound icon to control the timbre of its sympathetic resonance.