Crow, by the time the instrument builder has beaten the brass into shape, it has been annealed and tempered several times and NONE of its original resonant properties. I have built a couple of instruments and can attest to the craftsmanship being the deciding factor, not the material. Wood is a much different situation as it is a natural product with a grain structure and broad range of mass that influences the resonance. We would have to tap on chipboard to compare to alloys. Sterling silver is also sometimes used and has a different mass for a given wall thickness. The temper properties are also a bit different than brass. Stch: imperfect was the wrong word (that is my problem with bilinguality, sometimes the wrong word looks great!). IMPURE is what I meant in comparison to gold or silver where purity is a $$$factor$$$! Sorry The master will select one of the few alloys suitable for his instrument - more for cosmetics than sound. Schilke even called a certain brass alloy beryllium. It was possible to make the bell extremely thin with that material. Thin=lower mass= different sound depending on the temper. I am sure that somebody will eventually come up with a plastic that doesn't sound bad - and a ton of technobabble to support the idea that it is the greatest thing since the invention of the valve. Schilke did some interesting experiments with lead, steel and glass. There is some material on the internet at the Schilke Loyalist. I sell large IBM servers to medium and large businesses. The trumpet is just something that has posessed me my whole life. I am greatful to make a living from and be able to talk about other things! Cymbals are in fact cast and then spun. I visited the Zildjian factory. Pretty amazing stuff!