The register key is a key on the clarinet that is used to play in the second register; that is, it raises the pitch of most first-register notes by a twelfth (19

semitone A semitone, also called a half step or a half tone, is the smallest musical interval commonly used in Western tonal music, and it is considered the most dissonant when sounded harmonically. It is defined as the interval between two adjacent no ...

s) when pressed. It is positioned above the left thumb hole and is operated by the left thumb. The same key used in combination with the left first finger key which produces the written note A₄ (in

scientific pitch notation Scientific pitch notation (SPN), also known as American standard pitch notation (ASPN) and international pitch notation (IPN), is a method of specifying musical pitch by combining a musical note name (with accidental if needed) and a number id ...

) is used to play B♭₄. Some clarinets, particularly

bass clarinet The bass clarinet is a musical instrument of the clarinet family. Like the more common soprano B clarinet, it is usually pitched in B (meaning it is a transposing instrument on which a written C sounds as B), but it plays notes an octave ...

s and lower, have separate keys, or a more complex key mechanism, to control two or three separate holes for playing B♭, for playing the lower notes of the second register, and for playing the upper notes of the second register. The octave key is a key on the

saxophone The saxophone (often referred to colloquially as the sax) is a type of Single-reed instrument, single-reed woodwind instrument with a conical body, usually made of brass. As with all single-reed instruments, sound is produced when a reed (mouthpi ...

oboe The oboe ( ) is a type of double reed woodwind instrument. Oboes are usually made of wood, but may also be made of synthetic materials, such as plastic, resin, or hybrid composites. The most common oboe plays in the treble or soprano range. ...

that raises the pitch of most notes by an

octave In music, an octave ( la, octavus: eighth) or perfect octave (sometimes called the diapason) is the interval between one musical pitch and another with double its frequency. The octave relationship is a natural phenomenon that has been refer ...

when pressed, so that similar fingerings can be used for two different octaves.

Saxophone

On a saxophone, the octave key is positioned next to the left-hand thumb rest. Pressing the octave key opens the top tone hole in the neck of the saxophone. Alternatively, whenever the G key is fingered, the top tone hole closes and a small tone hole is opened near the top of the body. Some baritone saxophones, notably those made by Yamaha, also have three octave tone holes. The third one is used to prevent a rough transition from G# to A.

Oboe

The modern oboe has two octave keys, sometimes three, often interconnected, the one for E5 to G#5 near the left thumb, and the one for A5 to C6 to the right of and above the front keys, depressed by the edge of the left index finger. Oboes are now available with automatic octaves. This involves extra keywork that frees the player from having to bother with an octave key at all. The bassoon has similar keys used by the left thumb, but these are usually only depressed at the attack of notes, or "flicked".

References

"Easy Steps to the Band", Taylor, Maurice D., 1985.

Saxophone

Oboe

References

See also