I know what you mean: a direct example of what was being discussed would help. The Dunedin consort have some very short excerpts from the Bach passions on thei

I know what you mean: a direct example of what was being discussed would help. The Dunedin consort have some very short excerpts from the Bach passions on their site, including the Herr, unser Herrscher chorus mentioned in the first paragraph. There is a longer video trailer available. I am familiar with large force performances of the Bach passions and found the small ensemble approach sufficiently interesting to purchase an actual recording.