1) Activity of choir members 1) Attuning 2) Balancing 3) Concurrent 4) Matching 
• (p. pr. & vb. n.) of Harmonize
harmonizing 1. To bring or to come into agreement or harmony. 2. To provide musical harmony for (a melody); to sing or to play in harmony. 3. To be in agreement; to be harmonious. 4. To bring into consonance or to relate harmoniously.