I had a short gig to record a chorus (and reinforce them as necessary). At the very last moment (aka while we were loading in, a half hour before the house was to open) we changed from Clavinova to a Baby Grand, and moved the guest star 'cello quartet to the center of the horseshoe. Oh, and wrapped the horseshoe around at the ends because the singers couldn't hear each other (even before the 'cellos fired up!)
So the resulting stage plot looked like this:
So my primary mics for trying to get singers up over accompanists were three condensers set at chest height and crammed in between singers and instrumentalists. My primary recording device was a stereo set on the tallest mic stand I had available.
Unfortunately the nice mic bar we used to own had gone missing. So I taped the pair of Oktava's to one of the home-made brackets for my mini monitor speakers, in an arrangement I promptly christened the "ORWTF." (It was actually more like a narrow A-B setup, given the limitations of my improvised rig.) An A-B stereo pair depends entirely on timing differences for localization of sound sources; as contrasted with XY which is purely level-based (plus some tonal differentiation). The biggest problem with A-B is that it doesn't collapse well to mono; you get phase cancellation.
On the second day I added a spot mic inside the quartet; again improvising with the black electrician's tape and a table-top stand to make an XY pair sitting on the floor. Had I the gear, I would have used either a crossed pair of figure-8's, or an MS pair. The intention here was just to give me a spot mic with some localization to increase my available options when I go to mix down the multis.
The piano was on no-stick, with the front third folded back to expose the hammers. If it had been alone in a room I would use a large diaphragm condenser four to six feet above the lid. Instead I stuck a mic a mere sixteen inches from the tiny slice of exposed strings.
The only good luck I got was that on the first performance, the singers managed to end up grouped around my large condenser -- which I'd put in an omni pattern for that location. This was pure chance and not repeated, however. I've mentioned to the conductor that if they continue to work with instrumentalists, they either need to rethink where they use pianissimo, or start including awareness of microphones in their stage choreography.
Oh, yes. And all this listing of brands -- two Behringer B-5's, two CAD CM217's (actually, one, as the other went bad and I taped a Karma silver bullet on to it with yet more black electrician's tape) -- sounds like I was making careful choices. I wasn't, really. This is what I had available. But I will add that I've used both the Behringer's and the Oktava's before in similar roles, and the PG-81 has become my go-to mic for piano (although I recently heard a very nice result from an MXL on a grand on short-stick.)
So far the recordings sound decent. I record in Audacity for stability and options. The first step is hand-editing to take care of loud clapping, loud random noises and equipment noises that may be on the tracks -- Audacity is handier for this kind of point-edit. Then I normalize and export as individual mono tracks.
Sure, you can tame some stuff with compression. But one-of-a-kind events (like someone knocking into a mic stand) are better treated locally, not globally. And most compressors don't kick on instantly; they leave the first transient. In the case of a pop -- or a hand clap -- the compressor may pull down the average of the peak, but it will still leave the clipping-level peak intact.
In CueBase, I pan the tracks and chop and trim down to individual songs, and (often) re-normalize the individual slices. Then on a per-song basis I adjust pan, EQ, level, and effects. For some situations I'll need to draw automation curves as well (usually level, as when I have to ride a too-soft solo.) This particular concert looks easier than most; they didn't have much in the way of solos and they didn't move into so many different positions (not like last year, when they arranged themselves around the audience for one number and entered singing on another).
I'm hoping, in fact, to basically use my AB pair, unsweetened, and bleed in just a little of the spot mics where necessary. I listened to the four "solo" numbers by the 'cello quartet, and although it is a good concert hall sound on the ORWTF pair, the closer position of the XY pair at their feet is a much more exciting sound. Almost certainly, my final mixdown for them will be a combination of both.
The most complex thing I'll probably have to do is some very small time offsets -- since the spot mics are hearing the sounds up to 20 milliseconds before the area mics.