Like all the woodwinds the clarinet is very well suited for combinations with other instruments. Its sound is adaptable enough to produce an excellent tonal blend with all instrument groups. A particularly good blend is achieved with the horn.
Clarinet + woodwinds
Clarinet + flute
Played in unison an overall sound results which is at once mellow, bright and lustrous. Low notes played in this combination sound particularly warm and rich. In octave combinations the clarinet usually plays an octave below the flute; indeed it plays two octaves lower when combined with the piccolo.
Clarinet + oboe
Very full-sounding in unison as well as in octaves and in chords. In the low register the stern and acerbic properties of the oboe are more prominent, in the upper register the mellow clarinet. Because the clarinet’s compass in the low register reaches almost an entire octave below the oboe the clarinet also plays an octave below the oboe or in unison with the English horn.
Clarinet + bassoon
Play mostly in octaves. Because the clarinet’s sound is related to that of the bassoon and the oboe it supports the blend of those two instruments. The clarinet playing in the low register in unison with the bassoon is a little more prominent thanks to its darker and very powerful sound in this register.
Clarinet + brass instruments
Clarinet + trumpet, trombone
Clarinet + trumpet produce a very bright effect especially when the clarinet is playing in the upper register.
Clarinet and trombone combinations do not produce a very homogeneous effect.
Clarinet + horn
A mellow-sounding blend in unison which increases in brightness the higher the notes are that the clarinet plays. The clarinet playing one or two octaves above the horns also produces a full sound.
Clarinet + stringed instruments
The clarinets and strings combine to produce a very intensive blend.
The clarinet often plays an octave above the strings. If it plays in its highest (fullest-sounding) register the sound combination attains great volume.
Clarinet + cello
The cello is the instrument best suited for playing in unison with the clarinet which plays in its low and middle registers.
Clarinet + singing voice
Especially in opera the clarinet is often used in combination with the soprano or alto voices. The clarinet frequently accompanies the singer in unison or together with the viola an octave lower.