theme of the music, or most commonly a differently designed version of the regular band uniform, often employing different colors (especially white) or features such as capes. Some (especially at the college level) still employ the tall wool-lined shako or much larger bearskin (both often derisively referred to as a "Q-Tip hat"). Sousaphone players may use a military-style beret or entirely forgo the use of a head covering, as most hats may be in the way of the bell. Some auxiliary groups use uniforms that resemble gymnastics outfits: Often, these uniforms are themed, drawing inspiration from the music. Many auxiliary groups change the outfits they use from season to season based on the needs of the band, although some that do also have a "base" uniform for occasions such as parades or other ceremonies. Rehearsals Music for parade and show bands is typically learned separately, in a concert band setting. It may even be memorized before any of the marching steps are learned. When rehearsing drill, positions and maneuvers are usually learned without playing the music simultaneously—a common technique for learning drill is to have members sing their parts or march to a recording produced during a music rehearsal. Many bands learn drill one picture or form at a time, and later combine these and add music. Rehearsals may also include physical warm-up (calisthenics, running, etc.), music warm-up (generally consisting of breathing exercises, scales, technical exercises, chorales, and tuning), basics (simple marching in a block to practice proper technique), and sectionals (in which either staff or band members designated section leaders rehearse individual sections). When learning positions for drill, an American football field may be divided into a 5-yard grid, with the yard lines serving as one set of guides. The locations where the perpendicular grid lines cross the yard lines sometimes called zero points or gacks, may be marked on a practice field at eight-, four-, or two-step intervals. Alternately, band members may only use field markings—yard lines, the centerline, hash marks, and yard numbers—as guides (but note that different leagues put these markings in different places). For members to learn their positions more quickly, they may be given drill charts, which map their locations relative to the grid or field markings for each formation. In other groups, spray chalk or colored markers are used to mark the location of each person after each set of drill, with a