Final answer:
The modern day marching band has its roots in European military bands, with contributions from French and British influences, and was further developed by iconic composers like John Philip Sousa during World War I.
Step-by-step explanation:
The modern day marching band traces its origins back to military bands, with a significant development attributed to European military ensembles, particularly from France and Great Britain. For instance, the depiction of an older man leading a musical group with a staff as described in Figure 8.2.40 seems to allude to ancient ceremonial practices which influenced later military and religious processions. Notably, the structure of military bands and their role in maintaining morale was prominent during the vast mobilizations and reforms of the U.S. Army in World War I, as in the case of the 'Harlem Hellfighters' and the use of popular patriotic songs composed by figures such as John Philip Sousa, who specialized in marches for military bands and whose piece 'Stars and Stripes Forever' became among America's most beloved patriotic anthems. During this era, bands not only entertained troops but also played a key role in military ceremonies and parades, capturing the spirit of the time and building a sense of identity and unity, as seen in Figure: American, British, and Japanese Troops parading through Vladivostok.