Andy LaTorre enquired : "Now here is a big question: What can one use
as a mouse repellent?  In other words, what can be put in the bottom of
an organ console or piano which would repel mice?"

My neighbour's cat, Tyson, is available for hire at very reasonable
rates.  In one day he will not only strip out all rodents within
a square mile but will bring the remains home for inspection too,
I guarantee it.  Warning -- he also threatens small dogs with instant
death.

John Farrell
http://homepages.tesco.net/~stridepiano/midifiles.htm