I’m leading a singing workshop tomorrow. I know I will have 35 singers, seven of whom are men. Five of those are tenors. That means that I can choose song arrangements accordingly. But what happens when you’ve no idea in advance which voice parts you’ll have? Usually I would expect most of the men at my workshops to be baritones, with a few basses. I rarely get many tenors. So it’s great to be forewarned about tomorrow. When I lead a workshop open to the general public, I will only know how many male and female singers will be coming,...