Possible Clues:

• John Philip —, American march composer
• 'The Army Goes Rolling Along' composer
• Thus America presents one of its composers
• John Philip —, march composer
• "The Liberty Bell" march composer
• 'The Stars and Stripes Forever' composer
• 'The Thunderer' composer
• Man called the March King
• American student goes round America with a particular musical instrument
• Musical 'phone' namesake