on a single page

[Steffen Pfundmaier]

Hello together,

since a couple of month I'm using lilypond and I like it more and more. 
For my lessons ( I'm teaching viola) I often need to combine various 
small pieces on a single page. How to do that?
Each one of this file.ly is looking like:

\version ...
\header { ...}

upperVoice = \relative c' { ...}
lowerVoice = \relative c' { ...}
\score {
    \new Staff {  \upperVoice }
    \new Staff {  \lowerVoice }
    }


Every file is working well alone. How to combine them fast without 
having to change to much?  The next time I need another combination of 
this litttle pieces for another student.
Or how I have to write every file that I can combine them fast?

Thanks a lot

Steffen