Cantu in Paghjella is a traditional Corsican practice of polyphonic chants, which has been recognized by UNESCO as Intangible Cultural Heritage (ICH) and registered in 2009 on the Emergency Safeguarding List. Cantu in Paghjella, combining three male vocal registers, represents a pillar of Corsican culture and is performed a cappella on various festive, social and, religious occasions. The main objective of the I-Treasures project is to develop an open and scalable platform to provide access to ICH resources in order to enable the exchange of knowledge between researchers to contribute to the transmission of rare know-how of living human treasures, by learning traditional songs, such as Cantu in Paghjella. This article presents the work done with the singers on the recording and transmission of this type of song with several voices. We will discuss technologies to save and transmit Corsican polyphonic singing, including a study prior to the collection mission to gather relevant testimonies of traditional singers on the different aspects of their vocal practices and techniques. We will then present the use of our new data capture system using a multi-sensor headset that allows simultaneous recording of multiple voices and synchronization of acoustic and articulatory data. We will see how this work can not only contribute to local initiatives aimed at improving access to sound data, but also to safeguarding measures of UNESCO.