Very nice job on the videos. Takes courage to take criticism from colleagues. And if anyone says you sound like rubbish should be banned. Looks like there is tension in the breath. And that means exactly what is says. The breath should be as relaxed as possible(and then some). Breath low and what I mean by that is taking the breath below the belly button. It should feel as low as possible. It should feel as if your belly is bloated and you will feel it around to the lower back as well. The reason why we take it low is to keep the chest and throat relaxed. The diaphram should be the only thing moving the air. Everything else just gets in the way. When you put air in the horn it should flow from you very relaxed. There are a couple great videos on youtube showing this. Don Jacoby "Jake" Trumpet Clinic - YouTube This one is by Don "Jake" Jacoby. It's just audio only. But he really nails it. The other is an impromtu lesson by Jim Manly Jim Manley - Approach to Air & Airmen of Note trumpets - YouTube Very awesome demonstration. Just shows not only how but why.