Quadrilateral is a percussion quartet for the indoor or outdoor marching drumline ensemble. The instrumentation requirements are two marching snare drums and two sets of marching tenor drums (quints). All playing is in the rudimental style and all parts are reasonably balanced and written at an intermediate to advanced level. Techniques involved include flams, diddles, hertas, sweeps, swiss triplets, etc. Musically, this quartet utilizes both unison and complex interwoven rhythmic figures in a variety of instrumental textures. A rewarding and exciting piece for the performers and audience.