This is a simple and yet very powerful singing tip. Keep in mind that we don’t sing consonants, we sing vowels. Our vocal folds can only produce vowels, and proper formation of vowels is one of the keys to singing mastery. The most common mistake we make we either vocalizing during our vocal exercises or when singing songs, is to lose control of the vowel. We do this a couple of ways.
First, we may simply be using the vowel sound that we use when we speak the same word. In singing, we shape vowels differently than we do when speaking. This is one of the biggest differences between a beginner and an advanced singer. Second, our vowels can “splat” or “squeeze” if we are making a vowel sound right at one of our difficult passage points that requires a modification in the vowel so that we can navigate past that point.
Additionally, one of the best family of exercises we use regularly at Vocal Nebula is called “Closed Mouth Vowels”, or CMV’s. Other voice coaches may not take these exercises as seriously as we do here, and will call the exercise simply a “warm up humming” exercise. The student receives instructions to hum and to make a “mmmmmm” sound. This is incorrect. The “mmm” sound is only made at the very start of the phrase and is handed off to whatever vowel sound you choose to make for that phrase. Even with your mouth closed, you are still making the vowel with the false folds in the exact same way you do when your mouth is open. So keep the vowel in mind and stop thinking about the “mmm” or the “nnn” that you used to start the phrase.
This will accelerate the results you see from your vocal training. Keep your mind always on the vowel and the needs of the vowel to modify at certain points in your range.