My vocation/formation directors in the monastery were bi-ritual (Ge’ez/Latin).
I know the drums are significant, but don’t know the explanation for them. The music is rooted in the traditional music of the area (very impressive, if not what we would consider as reverent in an American parish).
As to language, they primarily still use Ge’ez, however they also would use Tigrinya (sp?), the local language. I do wonder if they will start using English, as the second generation children do not speak either traditional language.
You may be able to get in contact with Fr Awte Weldu through Our Lady of Fatima Cistercian Monastery in NJ.