% LSR: http://lsr.di.unimi.it/LSR/Item?id=956
%% => http://lilypond.1069038.n5.nabble.com/Clef-change-at-the-beginning-of-a-staff-tc168090.html 
%% see also: http://lsr.di.unimi.it/LSR/Item?id=792

\relative c' {
  %%  Start with a bass clef :
  \clef bass
  %%  Use a hidden grace note:
  \once\hideNotes\grace c64
  %%  Adjust the clef spacing:
  \once\override Staff.Clef.X-extent = #'(1 . 2)
  %%  Put in the treble clef:
  \clef treble
  c4 c c c | c1
}