John Philip —, US composer of marches The Stars and Stripes Forever and Semper Fidelis (5)
I believe the answer is:
sousa
(Other definitions for sousa that I've seen before include "Composer of "The Stars and Stripes Forever"" , "John Philip -, composer of famous marches (The Stars and Stripes for Ever)" , "John Philip ---, US bandmaster" , "American composer known for marches" , "March man?" .)