The event seems to have involved a nightwalk around the mountain with various light and sound happenings - seemingly including the sounds of ancient horns. Hence the book includes an essay by ancient musical instrument expert John Purser, Paths of our Ancestors, which discusses their significance:
'there were much older instruments belonging to the peoples who herded cattle in Ireland and Scotland - the beautiful curved bronze horns from the Bronze Age itself, of which many still survive. The orginals - some still playable - are derived in form from the horns of cattle and can reproduce the sounds of cattle among other things. They date from three millennia ago and, with their accompanying rattles shaped like a bull's scrotum, they carry with them a fertile memory of a great herding culture...
Besides being able to imitate the sounds of cattle, bronze horns can also convey a sense of fear or of magic - sounds which relate to the mythology of the cattle, in to which much that is magical is woven. That deeper sound world which is shared by all living things, in which the sounds of warning, or enticement and allure, have some strange commonality beyond analysis, will carry to you the sounds of our ancestors, human and animal, from deep in their throats. Listen in silence and you too may, in imagination, follow those paths where human and animal, reality and myth, meet without embarrassment in natural companionship'.
The notions of the horn section remains at the heart of soul and jazz, even if the instruments no longer resemble their animal ancestors. But the name itself is a reminder that some of the earliest musical instruments were made from cattle (from actual horns, and in the case of drums from the skin of cattle), partly in imitation of the sounds of these creatures. Later bagpipes too were made from animal skin, as well as the belly of some stringed instruments.
I was reminded of some of the primeval power of music last week, and indeed of Test Department, when I came across this lot in Glasgow's Buchanan Street. Clanadonia are self-styled 'Tribal Pipes and Drums band', and they do make a fearsome sound.