Trumpeting Questions

An exploration of the Chatzozros and their significance

The silver trumpet found in King Tutankhamun’s burial chamber

For years I was intrigued by the Chatzozros mentioned in this week's parsha. 

Moshe was instructed to form two silver trumpets out of a solid piece of silver. These trumpets were used as a signal for when the Bnei Yisrael would move their encampment forward and when Moshe would need to gather the people. 

There are a few things that I am curious to understand. 

1. The Torah goes on to detail when there were long blasts and when there were short blasts. The Tekiya, long blast, was for calling everyone together or to announce the Chodesh or Chagim.  The Teruah, short blast, was for moving the encampment or going out to war. What is the significance of the blasts? Why does going out get signaled with a Teruah and coming together signaled with a Tekiya?

2. Why were these trumpets only used by Moshe and hidden shortly before his death¹?

3. What is the significance of a trumpet? Why not a drum, flute, violin, or any other musical instrument?
   

4. What…