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.
What is another factor of the modern Drum and bugle corps marching technique?
members of the battery must keep their entire bodies facing forward at all times due to the nature of their equipment.
What are members of the battery in the modern Drum and bugle corps supposed to do when marching?
crab walk or oblique, where the legs cross over one another to facilitate sideways motion; the technique is used mostly by battery, but in rare instances by the hornline.

Question: Why can horn players twist their bodies?
Self-contained rewrite: Why can horn players in the modern Drum and bugle corps twist their bodies when marching?