Sound travels in the direction of cooler air.  This is called refraction.  The effect is accentuated at higher frequencies due to their shorter wavelength.  Sound outdoors does indeed travel straight up rather than out.  That is also why sound travels further laterally on a cloudy day due to the insulation.  Inside it can be a little complicated.  In large groups sound does travel up away from the warm bodies and curves back down once it reaches warmer air toward the ceiling.  That is why the ideal mic position for an orchestra is about 9-12 feet above the conductor.  (though not having the bodies of the violinists block the sound from the winds is a more important reason)
 
For choir or vocalist spot miking, I tend to prefer the sound of microphones a bit lower because of the added warmth to the sound.  Brightness is not especially pleasing for vocal groups much of the time.  

 
https://www.youtube.com/watch?v=Pa11QYLci2I
 
https://www.youtube.com/watch?v=TN80JSWZGCY
 
https://www.youtube.com/watch?v=VTrPSBuYVJk
 
https://www.youtube.com/watch?v=Pa11QYLci2I

People are suggesting placing the mics when you haven't described the room dimensions. So, my suggestion is : group them in an equidistant arc, close X-Y pair about 5' in front of them - eye level. if you have 12' or higher ceilings then raise the mics to maybe 7'.

rumleymusic
What 4 mics do you have?

I'm new at this, and mics are the one thing I've (so far) spent little money on. Good mics are on my list, but at least a year away.
 
So, what's cheap and ubiquitous? Yeah, MXL. I have 3 990's and 2 991's, all cardiod. And bright. My Mogami Gold cables are better than the mics. 
 
In my defense, all I can say that I spent less than $200 on the lot.
 
Gibson SG bass to back up my Fender J Bass. Good mic. Gibson SG bass. Good mic.
 
Guess what won. Unh hunh.
 

Rbh
People are suggesting placing the mics when you haven't described the room dimensions. So, my suggestion is : group them in an equidistant arc, close X-Y pair about 5' in front of them - eye level. if you have 12' or higher ceilings then raise the mics to maybe 7'.

Thank you for generalizing it. Helpful, since I don't have a clue yet about the room. It could be anything from a small studio to an auditorium.
 
I'll be seeing the Pres. of NAU shortly (I may be a major donor, but I've had her and her husband over for dinner; we get along well) and plan to ask her for help getting connected to the Dean of the School of Music and then go from there. If at all possible, I'd like this to fit into not only their academic schedule, but also their studies. I'd love to get an original piece done just for this recording session. Networking has its benefits!

TheMaartian

Rbh
People are suggesting placing the mics when you haven't described the room dimensions. So, my suggestion is : group them in an equidistant arc, close X-Y pair about 5' in front of them - eye level. if you have 12' or higher ceilings then raise the mics to maybe 7'.

Thank you for generalizing it. Helpful, since I don't have a clue yet about the room. It could be anything from a small studio to an auditorium.
 
I'll be seeing the Pres. of NAU shortly (I may be a major donor, but I've had her and her husband over for dinner; we get along well) and plan to ask her for help getting connected to the Dean of the School of Music and then go from there. If at all possible, I'd like this to fit into not only their academic schedule, but also their studies. I'd love to get an original piece done just for this recording session. Networking has its benefits!

You might also have them staged 2 ppl deep - tactfully wamp the loud ones on the forehead until they wander to the back row.

Wow, I just listened to this (linked by Daniel above). Man, I'd be proud of that recording. Great balance and spread. Of course, it helps that they're great singers in a reverberant room.
 
Note how high up the main mics are. This is how I usually see it done, which always struck me as odd since it's a perspective no audience will ever hear. Maybe it's also in consideration of the pipe organ?
 

Thanks Bitflipper,
 
You are right, with a good group and a good room, it takes little effort to get a good recording, and can be done convincingly with even cheapo Chinese condensers. (Though this was with Sennheiser MKH8040's and Josephson C617set mics, and that certainly makes things sound better)
 
The height of the mics was in consideration of the depth of the chorus.  It is a little better perspective and more even front to back.  It probably did help with the organ as well though it wasn't very intricate on this piece.  
 
As far as perspective, personally, I say to heck with the audience, the best seats in the house are above the group.  

rumleymusic
... 
As far as perspective, personally, I say to heck with the audience, the best seats in the house are above the group.  

I hadn't thought of it until just now, but that perfectly explains why I preferred my Mezzanine Box seats at the Lyric Opera of Chicago. I had some one-off floor seats (for, for example, the 5-6 hour performances of Der Ring des Nibelungen). My seats were off to the side a bit, but the sound was wonderful.

rumleymusic
What 4 mics do you have?
 
I usually mic choral groups with a stereo pair at a reasonable distance (10-15 feet) back and space a couple to three wide cardoid or omni microphones closer up.  That way you can pick and choose your balance later on.  
 
If you are using cardioid mics, I would suggest the NOS pattern in a so-so room, or ORTF in a good room.  If there are soloists, make sure they stand center and closer to the main pair and you may be able to do without a spot.  If it is pop-like music, a spot may be necessary.   
 
For some miking examples:
 
This is a recent concert with just an ORTF pair on the ensemble and some instrument spots.  A little bit of bleed from the choir in the spots was a nice mix. (Choir on first two pieces only)
http://www.instantencore.com/music/details.aspx?PId=5123698
 
Here is a video of a professional choir with ORTF mains and some omni spots.
https://www.youtube.com/watch?v=-C2hkZpIiUM
 
Lastly here is a small baroque choir of 10 with 4 spots in conjunction with the main pair.
https://www.youtube.com/watch?v=cRFwfEMjQI4

OK, so I pulled the plug on a couple of new mics, the CAD GXL3000 multi-pattern condensers. Chinese-made, but got good reviews for audio and structural integrity. With the BP (Black Pearl) version shipping now, I found a couple of the non-BP versions for $91/each. Not the $69 price MF had on SDotD a couple of years back, but way better than the street price of $139 for the current BP (exact same innards, different look). And they come with shock mounts, so $90 seemed pretty good to me.
 
I plan on using them in an M/S pair, with one configured figure-8 and the other cardiod. If I can find some tall mic stands, I'll run a pair of 990 or 991 MXLs. That will max out the 4 mic pres on my audio i/f and give me two different perspectives to pick from and work with.
 
I've already ordered the mics, but any comments would, as always, be appreciated.