Final answer:
John Philip Sousa is one of the most famous composers of band music, known as "The March King" for his iconic patriotic marches, distinguishing him from other composers like Mozart, Prokofiev, and Holst.
Step-by-step explanation:
One of the most famous composers of band music is John Philip Sousa. Unlike composers such as Berlioz, Strauss, and Wagner, who were known for their progressive music that challenged the audiences, John Philip Sousa was famous for his patriotic marches. His compositions, like "The Stars and Stripes Forever" and "The Washington Post", are iconic in the American band repertoire and made him known as "The March King". This differentiates him in the field of band music compared to the other options, as Wolfgang Mozart was a classical era composer, Sergei Prokofiev a 20th-century composer, and Gustav Holst known for his suite "The Planets" but not primarily for band music.