I hear people describe themselves and others as tone deaf fairly often. It’s quite a judgment to make about oneself or somebody else because it is a real disorder, and once called “tone-deaf” a person might believe it even if they aren’t. We’re moving away from blithely referring to ourselves and others as having other disorders (learning disorders for example), and it’s time to limit our use of this term.
Amusia (tone-deafness, where people who are tone deaf are called amusics) affects about 4% of people (this number is up for debate). That’s slightly fewer than one in twenty. So it’s possible that you’ll work with someone who is genuinely amusical, but it’s still unlikely. Some people with tone-deafness get no pleasure from music at all and avoid it (from “Tone deafness: a model complex cortical phenotype” by Timothy Griffiths in Clinical Medicine).
Sometimes, we might feel inclined to chalk up somebody’s difficulty with music to tone-deafness. This is very true with kids, and adolescent boys especially. With transitioning voices, a phenomenon that you see is difficulty with matching pitches. When it appears day after day, it seems impossible that it could just be awkwardness.
But that’s usually what it is in my experience. The primary challenge is due to the changes of the vocal folds themselves. As Titze says in Principles of Voice Production:
During this growth spurt, adolescent boys find it difficult to control register. They often flip back and forth between their child voice and their new adult voice. This is understandable because modes of vibration are dependent on the shape of the vocal folds. As the folds become thicker and more rectangular, different muscle patterns need to be developed to control the modes of vibration. It is basically a trial-and-error process.
This anatomical change can mean intense difficulty accessing parts of the voice or matching pitch at all. Some people have blank spots in their voices or cannot access certain registers (I was unable to use my falsetto until I was about 19 once my voice changed).
In “Effect of Voice Change on Singing Pitch Accuracy in Young Male Singers” by Elizabeth Willis and Dianna Kenney the authors focused on matching intervals in boys whose voices are changing. On average, the boys couldn’t match an interval greater than a fourth and would be consistently flat. A fourth. I’m sure that hearing a group of boys singing an interval flat repeatedly is mind-boggling and frustrating, but it’s not tone-deafness.
I’ve worked with teenagers who do so poorly at matching pitch that they might be chalked up to being tone deaf. But often there was some other cause in addition to their growing voices. For example, there’s often a lack of recognition between the sound of the piano and the tone of their own voice. It’s hard for them to hear the piano play their note and then sing it back.
But as soon as I would sing their phrase in their own octave, they could repeat it back to me. So, yes, there’s a disconnect somewhere, but it’s not tone-deafness. There’s a big difference between the timbre of the piano and the timbre of the voice, and it takes practice to reconcile the two.
True amusics may have trouble discerning common melodies. So if someone can’t recognize “My Country ’tis of Thee” or “Mary had a little lamb” or some other common tune by melody and rhythm alone, then you might have someone who is amusical. But it is doubtful that those people would voluntarily sign up for a choir.
So I figure that if you have someone who’s a) drawn to choir in the first place and who can b) match any pitches at all in some part of their range despite major pitch difficulties and who can c) identify common tunes, then they should not be discounted as tone-deaf. There might be other factors at play, but they deserve our patience as music educators.