Altissimo

Altissimo refers to the register above the normal, practical range of a wind instrument. It most commonly applies to the saxophone, clarinet, and flute, but can be theoretically applied to any wind instrument with a defined, standard range.

The altissimo register often relies on altered fingerings, embouchure manipulation (including adjustments to the angle of the instrument and air pressure), and voicing techniques to produce pitches that are not typically achievable using standard fingerings. These notes are often unstable and require significant control and practice to produce consistently and with good intonation.

While the specific pitches considered to be in the altissimo register vary depending on the instrument and player, they generally lie above the highest notes readily playable with standard fingerings. For example, on saxophone, altissimo generally refers to notes above high F# (written). On clarinet, it usually refers to notes above high C (written).

The tone quality in the altissimo register often differs from that of the normal register, sometimes described as being brighter, more focused, or even having a slight edge to the sound. Effective use of the altissimo register often requires careful consideration of timbre and musical context to avoid sounding harsh or uncontrolled.

The study and mastery of the altissimo register is considered an advanced technique for wind instrument players.