Harmony is often treated as polish added after the important melody is written. In a group, it can be the drama. Two voices moving together tell us something different from one voice holding a note while another strains against it. Unison can sound like solidarity, discipline, disguise, or threat.
“In an ensemble project, harmony is evidence.”
That means vocal arrangement should follow the relationships. A chorus sung in perfect balance at the beginning cannot simply repeat after a betrayal. Perhaps one voice drops out. Perhaps another takes over a line she once supported. Perhaps the group earns unison only after learning that agreement is not the same as obedience.
I want the audience to hear the crew becoming a crew. Not because the mix grows larger, but because the placement of each voice tells the truth about who can listen to whom. In an ensemble project, harmony is not only a sound. It is evidence.