Plucked strings.
When the usual orchestral string quartet (Vns I, Vns II, Violas, 'Cellos, D. basses) does not make use of the bow, but plucks the strings with the finger, it becomes to my mind a new and independent group with its own particular quality of tone. Associated with the harp, which produces sound in a similar manner, I consider it separately under the heading of plucked strings.
Note. In this group may be classed the guitar, zither, balalaïka; instruments plucked with a quill, such as the domra,[9] the mandoline etc., all of which may be used in an orchestra, but have no place in the scope of the present book.
Pizzicato.
Although capable of every degree of power from ff to pp, pizzicato playing has but small range of expression, and is used chiefly as a colour effect. On open strings it is resonant and heavy, on stopped strings shorter and duller; in the high positions it is rather dry and hard.
[Table D] on [page 31] indicates the range in which pizzicato may be used on each stringed instrument.
In the orchestra, pizzicato comes into operation in two distinct ways: a) on single notes, b) on double notes and chords. The fingers of the right hand playing pizz. are far less agile than the bow; pizz. passages therefore can never be performed as quickly as those played arco. Moreover, the speed of pizzicato playing depends upon the thickness of the strings; on the double basses, for instance, it must always be much slower than on the violins.
In pizzicato chords it is better to avoid open strings, which produce a more brilliant tone than of covered strings. Chords of four notes allow of greater freedom and vigour of attack, as there is no danger of accidentally touching a wrong note. Natural harmonics played pizz. create a charming effect; the tone is weak however, and they are chiefly successful on the violoncello.
Harp.
In the orchestra, the harp is almost entirely an harmonic or accompanying instrument. The majority of scores require only one harp part, but in recent times composers have written for two or even three harps, which are sometimes compressed into the one part.