Complex sentence: Grand Central Station is a varsity level show choir ensemble at Central, and their marching band also particiaptes in the Maple Leaf Parade, a battle of area high school bands at La Crosse's Oktoberfest Parade.
Split into simpler sentences: Grand Central Station is a varsity level show choir ensemble at Central. The marching band participates in the Maple Leaf Parade, a battle of area high school bands at La Crosse's Oktoberfest Parade.