Integripalpia by Ed Carter: Ryevitalise in the North York Moors 

The cased caddis is a crucial food source for dippers, Ed has recorded a piece of music inspired by the dippers song, Their numbers have dropped by 39% in the past 25 years. The sound you hear is a recording of the dippers song, it’s speed reduced by 39%, and snippets recreated on a bamboo overtone flute. The flute represents the organic cylindrical nature on the cased caddis case.
More at NorthYorkMoors.org.uk