That's not a song or meant to be one.
It's called an adhan.
An adhan is a call to prayer which Muslims have to do 5 times daily and is quite common in the East.
So I think the movie was trying to depict Malcolm X's journey into that.
Secondly, towards the end it was actually performed wrongly in that clip.
An accurate version is here with subtitles: https://www.youtube.com/watch?v=3QOKG_JZ6fA
Hope that helps.