Altissimo is a musical term that refers to pitch range and frequency, particularly very high notes. However, some definitions are very specific in terms of which notes are altissimo and which instruments play them. Altissimo notes are those that begin on the G in the octave above the treble clef, or any note G6 or higher, when not referring to a specific instrument.
Some instruments, such as the piccolo, can easily produce these pitches. Except for the soprano and sopranino members of instrument families, they are usually beyond their range. For vocalists, these notes are often referred to as the “whistle register,” despite the fact that “whistle” tone production requires distinct physiology that is required at different pitch points for different individuals, and thus may occur before G6. Despite the fact that all voice types can reach an upper whistle register with proper training, only sopranos, or women with the highest voice class, can produce true altissimo of G6 and above.
Altissimo notes, according to a slightly looser definition, are the highest notes that any instrument is capable of producing, with some people limiting altissimo to woodwind instruments only. This definition refers to pitches that are outside of the instrument’s normal range. On the oboe, for example, G5 is considered the highest pitch, but oboists are experimenting with new fingerings and techniques to reach higher pitches. As a result, playing in this range is considered a more advanced or advanced technique.
For a player or singer, performing at an altissimo level poses unique challenges. For starters, the pitches are difficult to keep in tune for instrumentalists, and while fingerings are usually based on the instrument’s harmonic system, fingerings can be awkward and difficult to produce with facility. Second, instrumentalists must develop muscle memory for the precise pressure and embouchure shape required to make the instrument speak, which takes time and practice.
It is not only the performer who determines whether or not altissimo is possible for instrumentalists. The instrument itself is significant. Performers must select the appropriate mouthpiece and reed combinations for their mouths. They must also keep their instrument in excellent working order, as any air leaks can prevent proper fingering from working properly. Simply adjusting these factors allows some players to reach extreme upper pitches much more easily.
Vocalists are naturally limited by the shape and length of their vocal cords and supporting tissues, unlike instrumentalists who can experiment with fingerings to produce different pitches. Many vocalists’ vocal mechanisms are simply not built in such a way that they can reach the altissimo notes well. Because the amount of air pressure required to vibrate the vocal cords is exhausting, extended pitches may only appear once or twice in a work.
In the musical world, vocalists who can produce a clear whistle pitch are considered a rarity, and they may become known for their ability to reach the very top of their range. The soprano Lucrezia Aguiari, better known as La Bastardella, who sang for Wolfgang Amadeus Mozart and was said to be capable of reaching a C7, was probably one of the most famous examples of a singer for whom this was true. Mariah Carey and Georgia Brown are two more modern vocalists who are known for their whistle notes; Brown claimed to have reached a G10, but there is no proof of this. The ability to produce pitches around the true altissimo starting point, G6, is much more common — the Queen of the Night’s character in Mozart’s “Die Zauberflöte,” for example, requires a good F6 in the famous aria “Der Hölle Rache.”