The clarinet is made of wood, except for the valve mechanism which is made of metal. Sound is produced by a mouthpiece and the reed attached under it.

The instrument blends well also with thin musical textures. A soft tone can be produced at will, except for the higher register, which is impossible to play quietly. The instrument is very dexterous with wide glissandos and octave skips.

The clarinets are transposing instruments, the material written must be transposed either up or down. The most common clarinet has the Bb-tuning, others are A, Eb, C, D and the Bb bass clarinet.

The differences between clarinet's tonal registers are great:
- The lower register is warm and full (string-like or saxophone-like)
- The higher register is thin and more piercing

The transposition table:

Eb - Minor third down
Bb - whole step up
A - minor third up
Bass in Bb - an octave + whole step up

Recommended combinations:

The most used woodwind combination is the clarinet - flute, but it is recommended the clarinet is placed in the lower tones of a chord voicing.
Clarinet with trumpet (especially with mute)
Clarinet with string instruments

Problematic combinations:

Clarinet with oboe (produces easily a rumbling sound)
Clarinet below, flute above (the powerful higher notes can produce an out of tune effect)
Clarinet with bassoon can be even more problematic combination.