Sentence:  At intervals you behold the passage of sounds of all forms which come from the triple peal of Saint-Germaine des Prés. Then, again, from time to time, this mass of sublime noises opens and gives passage to the beats of the Ave Maria, which bursts forth and sparkles like an <WSD>aigrette</WSD> of stars. 
Meaning of the word marked with <WSD> tags:  A plume or tuft for the head composed of feathers and/or gems, etc.