The Choosing Dilemma: B Flat or A Clarinet in Different Keys

When it comes to orchestrating music, the choice between a B flat clarinet and an A clarinet often depends on the key and the context of the piece. Let's explore why this decision is vital and how to make the right choice for your composition.

Understanding Key Signatures

Orchestration books often mention that the B flat clarinet is more comfortable in flat keys. While this is a useful guideline, it’s not a strict rule. As a professional clarinet player, the ability to play in any key is crucial. However, for amateur players, flat keys can make their life easier. When writing out the transposing part for a B flat clarinet, you can take away two flats from the key signature or add two sharps, making it the obvious choice for flat keys.

For sharp keys, consider the A clarinet if a B flat clarinet would result in a key signature with more than four sharps. If the music involves frequent key changes or extended sections in remote keys, switching instruments might be necessary. For composers and arrangers, the choice should be based on ergonomics and player comfort.

Tonal Quality and Ease of Play

The A clarinet is known for its slightly darker tone compared to the B flat clarinet. Additionally, the A clarinet can go half a tone lower, making it more versatile for certain parts. On the other hand, the B flat clarinet sounds a bit easier in the extreme high register.

Mozart’s clarinet concerto is a prime example of why an A clarinet might be preferred. For the soloist, it is written in the key of C, which is much more player-friendly than A major. The modern soprano clarinets are transposing instruments, either in B flat or A. In wind bands, B flat is predominantly used, but orchestral players usually have access to both instruments.

Modern Clarinets and Compositional Considerations

Modern soprano clarinets offer subtle differences in tone quality. The A clarinet has a slightly fatter and darker sound due to its slightly larger size. When choosing an instrument, the primary consideration is ergonomics, and my rule of thumb is to avoid key signatures with more than three sharps or flats in the signature.

For example, in the key of F, a B flat clarinet is the obvious choice as the player would read one sharp (G). An A clarinet, however, would read four flats (A flat), making it less comfortable. In the key of B, an A clarinet is vastly preferable, with just two sharps in the transposition compared to seven sharps or five flats for a B flat clarinet.

While advanced players are not deterred by complex key signatures, it’s important to consider player comfort, especially for beginners. The more complicated the key signature, the more complex the fingerings will be. However, frequent changes of instruments just for temporary excursions into remote keys can be disruptive and unnecessary. So, if the player has an A instrument and only needs to play a few bars in a flat key, it’s best to avoid a switch unless it’s necessary for the music.

Conclusion

The choice between a B flat and A clarinet hinges on the key, player comfort, and the nuances of each instrument. By considering tonal quality, ease of play, and player comfort, you can make the right choice for your piece. For maximum clarity and player satisfaction, use a B flat clarinet for flat keys and an A clarinet for sharp keys, while keeping the written key signatures within reasonable limits for smooth and enjoyable performance.