Having never been to this church and wishing to go unnoticed, I slipped up to the balcony of the auditorium. I couldn't help but notice that most of the African-Americans in attendance sat up there as well.
It turns out that the brother and sister of this group were missionary kids in Africa, and the sister sang in the gospel choir at Wheaton College when she was a student there. That gospel choir's conductor happened to be in attendance, and they invited her on stage towards the end of the performance. They decided to sing "The Blood Will Never Loose It's Power."
Singing backup from the balcony were the African Americans in attendance and myself :)
It should be noted here that this church is actively involved in issues bridging race relations, so I do not want to paint a picture of segregation there. I am merely telling my experience on one given evening.