Oh. I see.
I've read
that Wikipedia article now.
Another perfect example of how some unknown dudes from the Internet change common (normal, settled) meaning of terminology.
I remember Wikipedia, when it at least tried to pretend it resembled scientific approach to making articles, used to put notes like "40 days without a link that proves this statement".
In this particular case "most scholars" are not defined and not confirmed in any way.
The same bullfeathers approach as in "there is a scientific consensus about climate change".
Ambiguous statements like two above are designed to cover up lies.
But I have a simple disambiguation method for this approach. It is in the same article! If
brass is NOT about material, then instruments must be called "
labrosones, literally meaning "lip-vibrated instruments". And later in the same article they write about different materials labrosones are made of.
So please, it is a common knowledge that brass instruments are made of brass. Hence they are brass, not labrosones.