Our writer for the Dancing in Caves project, poet Anna Selby, recommended to me Professor David Hendy's Radio 4 series Noise: A Human History, and particularly the first episode, 'Echoes in the Dark' which explores the fascinating association between the way in which sound behaves in caves and the sites that prehistoric humans chose for their artwork.
Hendy describes that “Wherever a cave sounds most interesting, you are also likely to find the greatest concentration of prehistoric art”, indicating an association between art and sound/music-making in caves.
Modern researchers, experimenting with making sounds in these special places in caves have described an effect: “quite unearthly...it seemed that the tapping had suddenly awoken some real yet invisible entity - like an avian spirit”.
Hendy goes on to describe “Prehistoric people would have had no understanding of the science of sound waves and reverberation. For them any echo would surely have seemed like a new sound, coming from an invisible being or spirit - something perhaps, from within the rock, speaking back, making its own presence felt. In other words, it would have seemed supernatural”. Hendy talks about the significance given to these places, which may have appeared to prehistoric humans like "gateways to [a] spiritual realm”, and there's a suggestion that trance-like dancing as well as music/sound-making may also have taken place in special parts of caves as prehistoric visitors tried to invoke the 'spirit' of the cave.
The full episode is no longer available online (although there is a book that accompanied the series), but there are a couple of snippets still online here:
http://www.bbc.co.uk/programmes/p0167502
http://www.bbc.co.uk/programmes/p01671w6
I love the simplicity of the sound in the second clip - as the description suggests "modern musical styles don't become attuned to these archaic places. Use 'primitive' sounds, however, and the singer's body and the cave vibrate together".