beats per minute the same smooth tone as a player marching at 180. The roll step allows for much better control of the upper body, and thus better control of the air support needed for playing. Some bands, and a select few drum and bugle corps, use a bent-knee variant of roll step, usually known simply as bent knee, in which the members roll from heel to toe but lead the next step with the knee instead of the foot, then planting the heel of the next foot by straightening the leg. High step The high step is a style of marching used by many colleges and universities, including most bands of HBCUs and the Big Ten. Four primary sub-variants of the high are used: The ankle-knee step involves bringing the foot up to the inside of the leg to the knee before coming down and forward. This is the style used by most bands from HBCUs. The chair step involves lifting the knee until the thighs are parallel to the ground, and with toes pointed downward. When the leg is elevated to its maximum height, a ninety-degree angle exists between the torso and the thigh, as well as between the thigh and shin. The leg is then lowered, and this is repeated in an alternating fashion between the legs. This style is used by many schools in the Big Ten. The extended high step, much like the chair step, involves the thigh being parallel to the ground and perpendicular to the body, but instead with the shin extended outward at a forty-five-degree angle from the body and with toes pointed downward. The leg is then driven quickly back to the ground while the other leg repeats in this fashion. The "stop-at-the-top" is a style similar to the chair step and is currently used only at the University of Wisconsin Marching Band. It involves bringing the leg up so that the thigh is at a 45-degree angle with the ground with the toes pointed as far down as possible. While the chair step is almost always used as merely a special decorative step, stop-at-the-top is the Wisconsin band's default marching style. An integral part of this style of marching is known as stop action, meaning that all movement ceases momentarily at the apex of each step. This requires a band to have a great deal of stamina, though is effective