I started with a cone for the bell of the trumpet, resized it, then extruded it backwards with an inner set of faces to prevent that back faces from being culled out and leaving the inside of the trumpet invisible.
I then worked on the mouth piece by taking a cylinder and resizing it, extruding it, and reversing any faces that got warped in the process.
The curve was the hardest part, I tried using curve tools and extruding, but copying a portion of the faces on the part that connects to the bell, then moving a copy below the original, and another copy angles in-between worked to get a curve after bridging.
The same Method was used for the other air ways.
But the slide was bridged then extracted and the faces were extruded into the previous faces that they were connected too.
The bar that holds the mouth piece is a copy of the bar that connects to the cylinder. It was extruded to be just big enough to hold the tail end of the mouth piece.
For finer detailing I bridged Certain parts of the keys to one another, so all connections are not the same. I like squared of looking things so I tried to make sharper edges where I could.
I also added a few seems. My references had more, but adding more with the brushed silver and copper look just felt off. I guess less is more in this case.
I also added red accenting. (render quality was scaled back since I just wanted to show the colors together)
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