Sometimes a song phrase feels easy to sing for a few notes and then suddenly feels awkward. The note itself isn’t too high, but the tone gets tight, the vowel shifts, and the words become hard to articulate. In some cases, the note itself isn’t the problem. Your jaw or tongue is working overtime, and that’s affecting how well you’re able to sing a phrase.
If you try to make a bigger sound by opening your mouth aggressively or keeping it in a set position, you might find that your jaw pushes down or pulls back. Instead of moving with each vowel and consonant, the jaw tension might affect the stability of a held note or interfere with the articulation of a group of words that have to be sung quickly. Loud singing can make the tendency even more prominent because loud notes tend to draw more muscular effort.
Another problem can happen with the tongue. The tongue moves around when you sing words, but if it’s tense, you might find that it presses against your teeth or against the bottom of your mouth too much, and the base of the tongue feels stiff. You might find that a vowel that sounds open and clear on an easy note turns narrow or distorted on a higher one. The melody might also be harder to hit because you’re having to sing the right notes while also fighting extra tension in your mouth.
To investigate, pick a short song phrase that you find a little awkward but that doesn’t require any difficult notes. Sing the phrase once with words and listen for where your jaw or tongue feels like it starts tensing. Next, hum the phrase. Finally, sing the phrase on one comfortable vowel, such as “oo” or “ah.” If the phrase feels easier without the words, part of the issue is likely articulation and the way you’re forming certain vowels and consonants, rather than pitch alone.
Sing the phrase again using a mirror and see if your chin juts out, your jaw opens too widely on one note, or your neck also moves along. Use a moderate volume and don’t sing the whole song; just repeat the difficult part. You can also record the phrase and listen for where the vowel quality or tone changed when you felt your jaw or tongue getting tighter.
Don’t attempt to keep all of the muscles from moving when you sing because singing requires motion, particularly when you’re changing words and vowels. What you’re looking for is whether your motion helps the phrase, or if the motion happens because you’re unconsciously tightening up every time you come to a note that doesn’t feel familiar. Pause briefly between attempts to sing the phrase, because repeated singing will only reinforce the motion you don’t want to make.
When you go back to singing with words, compare your second attempt to the first. Is the vowel easier to hear? Is your jaw more relaxed than when it’s wide open? Is your tongue less tense as you sing toward your target pitch? These details give you something to focus on the next time a song phrase feels more challenging than the notes imply.