The NPR field recording of Daniel Bachmann is one of my favorites. NPR knows what they are doing, the entire environment and recording chain for a live recording is important: the room (most important in this case), mics, mic placement, preamps, and post production editing. NPR seems to like using a couple of shotgun mics for their Tiny Desk concerts. I have watched quite a few of these recordings, and being interested in live recording I like to see what equipment they are using. You would think that they could afford to use just about any mics they wanted, but all I have ever seen is two shotguns. If you observe closely part of the sound engineering is to arrange the band members and their instruments in relation to the mics, so the shotguns pick up primarily the vocals with the instruments at a slightly lower level, rejecting other sounds to the rear and sides. Sure, you could mic everything and spend a week mixing it down, but the KISS (Keep It Simple, Stupid!) principle seems to apply here, get a quick and dirty recording that is good enough and throw it up on the website.
NPR had already recorded Bachmann in the Tiny Desk concert series. Apparently they were so blown away by his playing they wanted a special recording to highlight one of his songs. They first looked for a room to record it in, and selected Stratford Hall, fortunately close to NPR in Washington DC and Bachmann's home in Fredericksburg, VA, and having a lot of history as the ancestral home of Robert E. Lee as well. It's a nice big room with a high ceiling, lots of hard surfaces, very "live", and ideal for an acoustic recording. Again, they could probably use just about any mic configuration they wanted, but they elected to stick with what worked for them and just used the two shotgun mics. Placement of the artist and mics here is critical. The actual make and model of the mics is not so important here, but I would guess they are Sennheisers. I imagine they must have experimented with some different setups, but they settled on seating Bachmann about a third of the way down the center of the room, positioning the first mic about 2 feet in front of and just to the left of the guitar, and positioning the second mic back about 15 feet and further left of the room center. I would imagine the mic placement was influenced by the need to video the entire concert. The video camera(s) were placed in the doorway to the next room, so positioning the mics in the center of the room was not possible. The first mic gives them a direct guitar sound, and mostly by happenstance the second room mic has a unique room sound rejecting the front wall reflections (behind the mics), and getting reflections from the sidewalls at different times, giving two different reverb effects from the side walls, and also a smaller reverb effect from the rear wall. Genius! It's one of the best acoustic guitar recordings I have ever heard. I would have liked to position a stereo cardoid pair in the middle of the room as well just for a backup, and also tried some omni mics. However it turns out omnis would have picked up too many reflections, and perhaps cardoids as well, and mics placed in the center of the room would have interfered with the camera sight lines. The video production is first rate, with the camera(s) showing details of the hall like the paintings on the back wall, and zooming in on Bachmann's picking. The audio is synched perfectly with the video. I might have mixed in a little less of the room mic, but you can't argue with the result. A very nice job by NPR.
I don't work for NPR, and this is my analysis/opinion. If anyone else has different information or opinion of how they could have done this recording any differently, please post.