Teachers have learned a lot from the previous generation. We have learned that one of most detrimental things that can be said to a child is that they sound bad and they can’t sing. These children grow up into adults who have never experienced proper pitch matching in a song, and therefore have never really experienced the true joy of singing. They have been labelled tone-deaf.
Many children who have trouble singing on key are children with deep or lower speaking voices. Music played in elementary school is generally written in a key that takes the song up to and over high C. This can be challenging for children whose speaking voices are lower because their speaking voice is further away from their head voice.
When encountering a child who has trouble with pitch, it is necessary to first put songs in the key that is close to their speaking voice. This is where singing starts….at speech level. Then raise the key of the song by semi-tones with careful attention to the pitches that start getting higher than A above middle C. This is where their speech level must adapt to get the correct pitch. Do simple 5 tone scale exercises with them, and make sure they match the pitch. Give them lots of praise when they find the coordination that is necessary to find those pitches. Let them know when they are doing it correctly, so they know what they have to do …. over and over and over. Once they memorize the feeling of singing in their head voice, they will have much less trouble matching pitch.
The same theory goes for adults who have trouble matching pitch. An adult needs to find the right teacher who can help retrain the vocal cords to stretch out and thin as they go higher in pitch. It will probably take longer to retrain an adult than a child simply because an adult has been in the habit of singing off key for much longer. Their vocal cords have not been experiencing the coordination necessary to match pitch and sing higher pitches.