The unison playing is a technique on the (bowed) string instruments that involves simultaneously playing of the same pitch on two different, neighboring strings.
Usage and restrictions
It is worth to mention that not all unisons are possible on the string instruments.
The unisons that involve one open string are always possible on all string instruments (the lowest open strings are therefore excluded).
- For the contrabass: the unison is possible in extremely high positions (with care).
- For the cello: only unison which is possible is one that include playing with the thumb – and thus over the third position.
- For the viola: the first three positions are hard because the distance between the first and fourth finger is extreme – people can damage their hands. On some smaller violas and played by musicians that can stretch their fingers – it can be possible.
- For the violin: similar to viola but it is far more easier to perform the unison in the first position.
In the high positions it is very difficult to intonate on all instruments. It is recommended to introduce by a jump from previous unisons coming from a lower position.
Combining with voice
It is possible to use performer’s voice and simultaneously to play the same pitch. For all instruments that don’t use a mouthpiece (wind instruments) it is possible to use alternative sounds and vocals. Singing must include octave transpositions, so that the all human voice ranges are possible to execute the melody (soprano <-> bass voices).
In the following example the unison playing is combined with singing, thus creating three voices per one musician.