How did Johannes Brahms combine soloists and chorus in A German Requiem?

In A German Requiem, Johannes Brahms integrates soloists and chorus with a level of subtlety comparable to the relationship between orchestra and soloist in his concerti.1

The work consists of seven movements, which utilize the following vocal distribution:

• Chorus and Orchestra: Four of the seven movements are set specifically for these forces.2
• Vocal Soloists: The remaining three movements feature soloists, specifically a soprano in the fifth movement and a baritone in the third and sixth movements.2

By applying his mastery of rhythm, movement, and structural economy, Brahms successfully integrated these vocal elements into a grand, objective vision that prioritizes comfort for the living over traditional liturgical requirements.21