>Typesetting was much,
>much cheaper, but keyboard music had to be engraved, and the
>price for that didn't drop until punches were invented late
>in the century.
The only reason why keyboard music, or indeed any music with more than one
voice to a stave, "had to be engraved", seems to be because it was often
very difficult, not to say impossible, to read when typeset. Typeset
keyboard music goes back into the 17th century, but from the examples I
have seen I wonder how anybody could actually play from it.