Music engraving is the art

Art

Art is the product or process of deliberately arranging items in a way that influences and affects one or more of the senses, emotions, and intellect....

 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. Plate engraving, the process the term originally referred to, became obsolete around 1990. The term engraving is now used to refer to any high-quality method of drawing music notation, particularly on a computer

Computer

A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

 ("computer engraving" or "computer setting") or by hand ("hand engraving").

• Plate engraving: music was reproduced directly onto a zinc
  Zinc
  Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
  
   or pewter
  Pewter
  Pewter is a malleable metal alloy, traditionally 85–99% tin, with the remainder consisting of copper, antimony, bismuth and lead. Copper and antimony act as hardeners while lead is common in the lower grades of pewter, which have a bluish tint. It has a low melting point, around 170–230 °C ,...
  
   plate in mirror image.