NEWBIE: repeating whole tunes

[debian]

Please,

what is the best way to ask lilypond to create a midi file in such a
way that the _whole_ tune is played n times.  n will be passed from
the command line.  

I have written perl code to extract the essential parts of the tune
and create a new ly file with the essential parts repeated n times.
But the repeats are played an octave up each time.

I know this must be simple.

Thanks.

Joe