ill mention too that the design of singer mics being both channel in same spot aiming in different directions is not stereo but a simulation of voices coming from within your head
to be true stereo it can only be like this:
the rest the 99.9 percent recorded with two channels in the same spot is a conspiracy to drive people even crazier simulating voices coming from the center of your head when listening music with headphones
edit:
that 3 tenors sound is crap check how SPACED mics sound like: