Well I was practcing today at home and when I started playing I noticed this bad hissing sound was coming out and I couldn`t understand WHY!

So I thought something was wrong with the trumpet so I took it apart and I saw everything was fine, put it back together and it still was making that nasty hissing sound, so I got very sad saying to my self that I just suck and can`t play.

for 30 mins I was playing with that sad feeling that I suck while making that hissing sound.

I changed my seating position and that sound went away realizing that the hissing sound was coming from the music stand vibrating while I was palying!!!

Damn I got so happy learning that it wasn`t me
it took me so long to find out that it was the stupid music stand!!! LOL