Singing high notes often triggers a "fight or flight" response in the throat, causing the larynx (voice box) to shoot up. You get a strained, thin sound.
The 'Mum' Octave trains you to fight this habit. The "M" and "Uh" sounds keep your larynx steady, making it easier to move from chest voice to head voice without choking off the sound.
Actionable Step: The 'Mum' Octave
1. The Sound
Say the word "Mum" (as in "Mother"). Use a dopey, relaxed "Uh" vowel, like you are asking a question "Huh?".
2. The Feel
Feel the "M" buzz on your lips (mask resonance), while the "Uh" feels like a yawn in the back of your throat. Keep your jaw loose and heavy.
3. The Drill
Sing the octave arpeggio (1-3-5-8-5-3-1) using "Mum" for each note. As you ascend to the top note, think about "letting go" rather than "reaching up."
Practice with Vocal Driller
Why This Works
The "Uh" vowel keeps your larynx slightly lower than bright vowels like "Ee" or "Ay." By using "Mum," you encourage the larynx to stay neutral even as the pitch rises. The "M" also brings the resonance forward into your face ("The Mask"), keeping the sound out of your throat. Forward placement and a neutral larynx together give you safe, powerful high notes.