How to include a file/definition temporarily?

[Patrick Schmidt]

Hi all,

I have several files with definitions of guitar fret diagrams for  
various chord shapes (e.g. c-shape.ly, a-shape.ly, g-shape.ly, e- 
shape.ly and d-shape.ly). I can't include all of these files at the  
same time in the main file as quite a few chord alternatives start on  
the same pitch. How can I use those definitions only temporarily? I  
tried this:

cShape = { \include "c-shape.ly" }
aShape = { \include "a-shape.ly"  }

music = \chordmode {
  \cShape
  c1
  \aShape
  c1
}

Unfortunately this way the a-shape definitions overrule the c-shape  
definitions. If anybody knows a solution please let me know.

Thanks for any hint!
patrick