This is the traditional bugle call known as "To Arms", and it is used by military forces to order troops to assemble with their weapons. As such it serves a broadly similar purpose to calls such as Assembly and Fall In. See the links at the left to download the sheet music or audio files. More bugle calls are listed in our article about the history and cultural impact of Bugle Calls
The audio controls below allow you to play the mp3 version of To Arms (bugle call) or you can download the MP3 file. You can also download the midi version of To Arms (bugle call).
The image below is the first page of the sheet music, and here you can download the full sheet music for To Arms (bugle call) in PDF format.