G'day All,McGrath (and Kat): The Girl I left behind me/Brighton Camp is a well-known old tune - much used as a march in the British Army (and thus well-known to Irish serving in same). It also made a lot of mileage in the American Civil War.
We still use it as a dance tune, here in Australia and I can send you a MIDI, but I'm sure it would be in DigiTrad under one of its many aliases.
Reagrds,
Bob Bolton