The point (measured in age) when a boy's voice changes, from its piping treble to something else, has not always been the same. In fact, over the centuries it has changed dramatically. De Bacilly ('Remarques curieuses sur l'art de bien chanter', 1668) describes, among other voice types, the boy soprano. He concludes by regretting its passing between the ages of 15 to 20! Bach routinely used boy sopranos (and altos) into their late teens. The song 'Sweet Polly Oliver' (current in the 18th century, if not before) describes a girl's enlisting in the army, and passing herself off as a young man. How could that be? Not so far-fetched as you might think, since all those raw male teenage recruits would still have had their piping trebles, not a hair on their chins. At the beginning of the 20th century, trebles in the UK stopped singing the top line around the age of 16. These days it's variable: I have known boys become baritones at 11, and also continue as trebles until 15 and beyond. It always has, I think, been a moveable feast. For instance, Henry Purcell experienced voice-change at 14 (in the 1670s). At New College, in the top year of the Choir (at which point boys have their thirteenth birthday), there is generally one of the four going through voice-change, sometimes slowly, sometimes quickly.
The length of a New College choristership is timed to allow each boy to begin his next school before his fourteenth birthday. None in our stalls is older than thirteen, as a matter of course. So we don't feel too menaced by early voice-change. It is sufficient to have the year below hard on the heels of the top year, and also to start a whole year earlier with the probationers, thereby opening the window at the front end of the training process. Is there any age before which vocal training could not be started? I sense that at New College we can continue to aspire to excellent standards of singing and musicianship within the age-window we still have. What has obviously changed is that these trebles of 12 and 13 years are - relative to seventeen or eighteen year-olds - small in stature. Their vital capacity is less, their lung capacity less. So what they give us is going to be different. But it need not be less striking and satisfying than in the past.
At all costs, whatever the future brings, there is nothing we can do to arrest the development of boys. I had wondered for a time whether to persuade all my trebles onto a vegetarian diet, only to have the only boy already a vegetarian experience voice-change well before any of his peers! We could blame the hormone-rich dairy products, and we could certainly blame the parents (since there is a strong genetic component). It would however be tricky to audition the parent rather than the child! If the time does come when we have boys of 10 singing bass (or tenor), we will have to roll up our sleeves and give them our support. The crucial thing is to keep children singing, and singing really well.