What is a music engraver or copyist?
A music engraver or copyist is someone who prepares music for publishing. These days, it is done with a computer. In the past it has been done with plate engraving.
Wikipedia defines a music engraver as:
"Music engraving is the art of drawing music notation at high quality for the purpose of mechanical reproduction. The term music copying is almost equivalent—though music engraving implies a higher degree of skill and quality, usually for publication. "
This article also describes the definition of a music engraver.
You can also watch this video on the art of music engraving.