The Cuperto Exercise
Cuperto is an old Italian term which means singing through the proper alignment of the vocal cords along the thin edges. A singer trained on this can go up and down seamlessly through the registers lightly or dramatically without losing delicacy of harmonic. If too much cord mass is used then there is too much weight on the voice causing vocal problems. If too much air goes through the cords blowing them apart this causes vocal problems too. When the cords are properly aligned a natural blending of the registers occurs.
The Cuperto Exercise is an invaluable aid in singing