D90 recording concert
 

I've been hired to record a concert with my d90. And I'm going to record the audio with a decent Sony mic into audacity or something (what program should I use) and I'll sync it with video later. </p>
<p>My question is... Is the d90 battery going to last me for a little more than an hour of video capture plus some reception photos with flash after? I have a grip should I get a second battery?</p>
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