"Book of Hours" was recorded in the remarkable baroque central dome of the National Pantheon in Lisbon.
The musicians (and the audience) were 40 meters above ground level on a narrow circular balcony looking out over the abyss. The main sound source was a crystal bowl, played by João Silva, which was struck and resonated with a stick. Paulo Raposo processed these sounds and diffused them throughout the space via 6 channels, 4 of which were small self-powered speakers, arranged symetrically around the circumference of the dome. Carlos Santos also moved throughout the space and the audience with a small glass and a Tibetan bell.
The sonic interactions in "Book of Hours" aimed to reveal the inherently active qualities of the space, itself a performer in this acoustic dialog."