Problems with music-function for shortcut for \relative command

[Hans Sommer]

Hello,

Ich wrote a scheme function for getting a shortcut for the \relative command.



rel = #(define-music function                                              
                                    
     (parser location p notes)                                             
                                    
     (ly:pitch? ly:music?)
   #{
  \relative #p  #notes

   #})

I used it in with 
\rel c' {f4 g a b }

and get the following 

GNU LilyPond 2.16.2
Processing `base.ly'
Parsing...
addons.ly:46:12: error: wrong type for argument 2.  Expecting music, found
#<Pitch c' >
  \relative
            #p  #notes
test.ly:1:27: error: error in #{ ... #}
myscore = { \rel c' {f4 g a b }
                           }
Interpreting music...
Preprocessing graphical objects...
Interpreting music...Segmentation fault

Do somebody have a hint?

Thank you

Hans