I’m an 18-year-old mezzo-soprano. My vocal range is from an octave below middle C to high C. How can I expand my vocal range above high C properly without damaging my voice?
This is work to do in private lessons with your teacher. It will involve getting a more refined phonation, accessing the highest resonators and developing the breath support to be strong enough to prevent excess air pressure against the voice. The muscles between the lower ribs have to be very strong because it takes almost no air to sing high notes! This is a strength that develops over time.