A clarinet
The A clarinet is a type of clarinet that is tuned a semitone lower and is therefore slightly longer than the usual soprano clarinet in B. It is still used today in the classical orchestra alongside the B clarinet. Clarinetists alternate between these two instruments, often using the same mouthpiece .
From the late 18th to the early 19th centuries, clarinetists and brass players had to switch between a variety of differently tuned instruments. The current situation is a remnant of this tradition and essentially has the following practical reasons:
Most of the orchestral parts in music literature of the 19th and 20th centuries Century require alternating A and B clarinets, so that a semitone would have to be transposed if the corresponding instrument is not available (which many clarinetists can do). This avoids keys with many accidentals.
The A clarinet sounds a bit warmer and less brilliant than the B flat clarinet, which is sometimes required by composers, and sometimes also helps players to create appropriate passages without this instrument being prescribed. The lowest note on the A clarinet, the small C sharp (D flat), cannot be played by most B flat clarinets. In the case of German Bb clarinets, a so-called low-Eb extension would be necessary for this, which is inserted between the bell and the lower part and operated via the bell mechanism (resonance flap on the bell).
literature
- Walter Piston: Orchestration , New York: Norton 1955, pp. 172-173.