This is from an episode of “The nature of things” by David Suzuki; it features Dr. Gabor Maté who is an MD and author. He describes the use of the plant medicine Ayahausca for treating addition and depression.
The video is available at the CBC-TV site link given below.
A shorter preview is available on Youtube.
This blog site has some useful information about Ayahausca ceremonies : http://www.ayahuasca.tk/
There is kind of singing used during the traditional Ayahausca ceremonies, these songs are called Icaros.
Here are some sample Icaros.