\header{
filename = "preludes-2.ly";
-title = "2";
-opus = "BWV 939";
-% urg?? piece = "\\numfont 2";
-piece = "2";
% blz 10
%
% Six Petits Pr eludes
\grandStaff
\paper{ \a4 }
\midi{ \tempo 4 = 100; }
+ \header {
+ opus = "BWV 939";
+ piece = "2";
+ }
}