Altissimo

Altissimo (Italian for very high) is the uppermost register on woodwind instruments. For clarinets, which overblow on odd harmonics, the altissimo notes are those based on the fifth, seventh, and higher harmonics. For other woodwinds, the altissimo notes are those based on the third, fourth, and higher harmonics. The altissimo register is also known as the high register.
On the Boehm system flute, the first altissimo note, D₆, is played using the third harmonic of G₄. Fourth harmonics are used... plus