That icaro is an opener to the ceremony and calls in some very large spirits. There's been times when I've heard him sing that and a wave of barking dogs would cross the village until reaching the ceremony, as if something was coming to the ceremony and the dogs were alerting their owners. I'll try to listen to it more in depth and see if I can understand some of the shipibo words and maybe I'd have some more details for you. My Shipibo is at the level of a two year old shipibo child.
There are downloaders for youtube videos and file format converters, you could download it and make it into an mp3, or we could connect and I could get you the original.

Glad you like it.