My music director has a professional background and insists that everyone hold our Beta 87As under their chin, basically touching it, to get the best sound and prevent the pops. It looks like they're shaving with a Schick rather than a Shure. Can you offer me some more detailed advise (expand on answer in helps section) on how to properly hold this mic?
The mic position advocated by your director is incorrect.
Putting a mic under the chin leads to excessive breath noise and popping from the letter "T". A mic should never be placed directly below the nose unless one wants to record breath noises.
The proper position is off to one side of the mouth, but pointing at the center of the mouth. Look at any video recording with Frank Sinatra or Ella Fitzgerald. These great singers knew how to use a microphone correctly. Or watch Patti of the contemporary jazz duo, Tuck and Patti. She knows how to use a mic!
Today, 98 percent of pop singers DO NOT use the mic correctly.