Conversation so far:
What is the marching technique in the modern Drum and bugle corps?
As visual programs have increased in complexity, corps have developed and formalized various movement techniques.
How rigid are members of the modern Drum and bugle corps' upper torso supposed to be?
for maximum sound projection marching technique must not affect the rigidity of members' upper torsos.

Question: What is another factor of their technique?
Self-contained rewrite: What is another factor of the modern Drum and bugle corps marching technique?