A clarinet: is 1 half step in pitch below the B-Flat clarinet
Standard orchestral instrument used alongside the B♭ soprano. Because the strings play in keys that makes the B-Flat clarinet work very hard and use a lot of cross fingerings…. Playing the A clarinet for EXAMPLE: When the B-Flat clarinet has 7 sharps (the key of C-Sharp) the A clarinet is in the key of C (No sharps or flats) much easier…
The A clarinet has a darker tone and was used by the first 2 clarinetist in the John Philip Sousa band because they loved the sound… they simply transposed the music in their heads.. (Not an easy task by the way!)
It is required primarily in older, European classical music. Every serious classical clarinetist will own both a B♭ and an A clarinet, and cases holding both instruments are common. The A clarinet is not commonly used in band music.
