How can I know if a metal is brass or not?
Brass is not magnetic, brass is a yellow color
Do you mean the metal, brass, or the kinds of musical instruments called brass? The first metal alloy that was a kind of brass was probably invented about 5000 years ago. We don't have any way of knowing an exact year. For brass musical instruments, the early Romans and Greeks had musical instruments made of brass, more than 2000 years ago. Again, we don't have any way to know an exact year.
Brass is an alloy of copper and zinc. Copper is a metal itself. The copper in brass makes brass germicidal. The malleability and acoustic properties of brass have made it the optimal metal for musical instruments. Brass alloys are 90% recycled. Aluminum makes brass stronger and more corrosion resistant.