Use relative octave mode. By default, notes are specified relative to
middle@tie{}C. The optional integer argument specifies the octave of
the starting note, where the default @code{1} is middle C.
+@code{relative} option only works when @code{fragment} option is set,
+so @code{fragment} is automatically implied by @code{relative},
+regardless of the presence of any @code{(no)fragment} option in the
+source.
@end table
LilyPond also uses @command{lilypond-book} to produce its own