Please bare with me if my technical jargon is not quite correct.

Scenario: I have been asked to video a short (about 1 hour) video of a performance of traditional Japanese music in a very nice Japanese garden.
I will be using 2 cameras (Z1 and FX1)

The Z1 will be stationary and shooting the "big" picture.
The question is concerning the sound to the Z1.

The performers will have a sound mixer - controlled by a pro.
I will have the possibility of using a feed from the mixer.

What should I think about/take care to avoid/check before hand/not do under any circumstances.....etc.

e.g. Remembering to switch from onboard mike to the XLR feeds. I guess that phantom power should not be selected (is that correct),
How about volume? should it be on auto? etc. etc.

I would not use auto on the level. Make sure you are on LINE IN, NO phantom power. In fact, phantom will not be possible when you are line in. When I feed my FX1 from a mixer, I set the input to manual and the level on the cam at 5. I adjust the level on the mixer while watching the Camera on-screen meter. Make sure you are getting a clean stereo mix of all the inputs from the mixer. I have been pretty happy with the FX1 audio quality, your Z1 should be good. You also have nice XLR inputs so the connection should be solid. A long run of cable from the mixer might be a problem. Take some adapters for connecting into the mixer. Like RCA and 1/4" phone to XLR and some good XLR cables. Just be sure to constantly monitor it with a pair of Sony 7506's or simular. Have Fun.

Thanks Glenn.

The mixer will be quite close to the camera tripod.
Also the sound guy will be taking along a selection of extra connections for me.
I will meet him the day before..... so I should be able to iron out any problems then.

something else to consider... when live sound mixers do a performance, depending on the instruments being used and the venue, the mix out of the board may not be what you want.

e.g. A live rock band in a club - because the drums are producing a lot of noise on their own their level coming out of the board will be lower to compensate for the level already in the room.

I know nothing about traditional Japanese music or the venue, but I guess my point is what is coming out of the board may not be exactly what you want. I'm not saying don't take the feed, but ask the mixer about his mix and what you may have to do in addition to this feed to emulate the mix in the room.

Douglas, is the music live, as in live musicians. If so, why not think about piggy backing the sound with your own mics. If the instruments are close enough, maybe one of those phat condensors plugged up to a recorder. The worse case scenerio would be that you have audio from several different sources. I've been burned before by relying on one source for audio.

I bet, if the instruments are live, then a good condensor would do you well.