I'll also back the "beater" instruments. There are good sources of instruments out there that while not "top quality" will still sound decent, and there may just be times when "It's raining and I can't play my fiddle/bazouki/noseflute" won't cut it.

Case in point - I work the Renaissance Pleasure Faire, Southern CA. This year, first weekend, we rained out on Saturday, but not until the faire had opened and the first act at our stage was playing.

The musicians just grabbed the "spares" and went on. The bodhran was nearly inaudible (yeah, yeah - "what an improvement"), but the mando and bazouki sounded decent enough, what you could hear over the rain and thunder. The spares in this case were bought off a Hungarian luthier's site for this purpose - they're inexpensive, good enough for spares in ANY situation, but they also hold up during inclement conditions.

Of course, you will have to tune every ten seconds. And if you play in heavy enough rain you may have to empty out your instrument occasionally, or start stocking trout in it for fishing. But if you have no choice but to play in bad weather (contract, whatever), spares definitely help.

M