# register key

> thumb key on a clarinet to raise the pitch a twelfth into the high register

**Wikidata**: [Q3774659](https://www.wikidata.org/wiki/Q3774659)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Register_key)  
**Source**: https://4ort.xyz/entity/register-key

## Summary
The register key is a thumb-operated key on clarinets that raises the pitch by a twelfth into the high register. This mechanism is essential for extending the clarinet's range and enabling pitch transitions between different registers.

## Key Facts
- Part of: clarinet
- Function: raises the pitch by a twelfth into the high register
- Aliases: twelfth key, Llave de cambio de registro
- Freebase ID: /m/0281qjj
- Subclass of: clarinet part, octave key
- Sitelink count: 6
- Wikipedia titles available in: ca, en, es, it, sh, sr
- Wikidata description: "thumb key on a clarinet to raise the pitch a twelfth into the high register"

## FAQs
### Q: What is the purpose of the register key on a clarinet?
A: The register key is a mechanism that clarinet players use to access the high register by raising the pitch a twelfth. It enables smoother transitions between different octaves and extends the instrument's playable range.

### Q: How is the register key operated?
A: The register key is typically operated by the player's thumb, though in some clarinet designs, it may be positioned for other fingers to activate. When pressed, it opens a specific tone hole that facilitates the pitch change to the higher register.

### Q: When did the register key become a standard feature on clarinets?
A: The register key became a standard feature on clarinets during the instrument's development in the early 19th century, as improvements were made to extend the clarinet's range and playability.

## Why It Matters
The register key represents a crucial innovation in woodwind instrument design that revolutionized the clarinet's capabilities. Before its implementation, clarinetists faced significant challenges transitioning between registers, often requiring awkward fingering techniques or alternate instruments for different ranges. The register key solved this problem by providing a reliable mechanism to access the high register, significantly expanding the instrument's technical and expressive possibilities. This advancement enabled composers to write more complex and virtuosic clarinet parts, contributing to the instrument's prominence in orchestral, chamber, and solo repertoire.

## Notable For
- Essential mechanism for accessing the clarinet's high register with a twelfth pitch increase
- One of the fundamental keys distinguishing modern clarinets from earlier single-key designs
- Critical innovation that expanded the clarinet's technical capabilities and repertoire possibilities
- Standard feature on all clarinet systems despite variations in specific design details
- Typically positioned for thumb operation, though some specialized designs may use alternative fingerings

## Body
### Technical Function
The register key is a specialized key mechanism located on the upper joint of the clarinet, typically positioned to be operated by the player's left thumb. When pressed, it opens a specific tone hole that creates a ventilation point in the bore, effectively shortening the vibrating air column to produce a pitch a twelfth higher than the fundamental note.

### Historical Development
The register key emerged during the clarinet's evolution in the early 19th century, coinciding with the addition of additional keys that extended the instrument's range and improved intonation across different registers. This innovation was part of the broader transformation of the chalumeau (early clarinet) into the modern Boehm-system clarinet.

### Design Variations
While the fundamental function remains consistent across different clarinet systems, the precise placement and mechanism of the register key may vary slightly between manufacturers. Some instruments may feature additional "register tubes" or auxiliary mechanisms to ensure clean transitions between registers, but the primary thumb-operated key remains the standard approach.

## References

1. Freebase Data Dumps. 2013