Work with the boundary, not against it
Explore each register separately, then cross the threshold with a short phrase and controlled volume.
- Sing a short pattern in chest register at a comfortable pitch.
- Repeat it lightly in falsetto register.
- Connect the two with a small step and no increase in pressure.
The boundary is useful information
Trying to make the entire range identical can hide the real action. Explore each register and the area where the sensation or sound changes.
Work separately first
A short phrase in chest register clarifies density and onset. A separate light falsetto phrase clarifies the upper action.
Cross with a small task
Use a short interval and moderate volume. If pressure rises with pitch, return to the separate modes.
Transfer into music
Find the same area in the current work. Sing it on one vowel, restore the text and keep the direction of the phrase.