Well...actually..it will work, but it wouldn't be what I would use.
for a live concert...if you are not getting a feed of the front of house board.....I would use an XY pair of cardioids, or something like the Rode NT4.
i have a couple more questions:
in this case which is a classical concert involving a violinist, cellist, pianist and a children's chorus audio or studio quality audio is not what the peson i am recording for wants. she said that if she did a studio setting would be optimal. For her live proeformances she just wants acceptable audio which could be used for archiving video and audio of concerts. also the number of insturments and people in each production varies so i would want to get a mic that could cover a wide range of sounds including spoken word.
also for a concert such as this would two or three mics yield the best quality for what they would be used for?