2. Convenience. Many passages, especially those in which notes of widely different range succeed each other rapidly, would be impracticable but for the use of higher positions, even for those notes which might, theoretically speaking, be taken in lower positions.
In a passage like this—
the three lower notes of each group might be played in the first position, if by themselves; but in connexion with the two high notes, the jump from the first to the fifth position, which is absolutely necessary in order to reach them, would make a smooth execution of the phrase, even at a moderately rapid pace, quite impossible. If started at once in the fifth position there is no difficulty at all.
3. The tasteful and characteristic rendering of phrases and passages requires a careful of positions, based on the distinct and contrasting qualities of sound of the four different strings. Where sameness of sound is required, the change from one string to another will, if possible, be avoided; where contrast is wanted, different strings will be used even in cases where one string could give all the notes.
A phrase like this—
though lying entirely within the compass of the first position, must, in order to sound as cantabile as possible, be played entirely on the 2nd string, in the first and third or second position alternately. In the first position a constant change from the 1st to the 2nd string would be necessary, and the phrase would thereby sound jerky and uneven, the very opposite of what it ought to be. Or this passage in Spohr's Scena Cantate Concerto—
if not played entirely on the sonorous 4th string, would absolutely lose its peculiar character. In other instances the meaning of a passage is only made intelligible by its being played in the proper position. The following is from Bach's Preludium in E (bars 13 and 14):—
In this instance, unless the whole of the lower part is played on the 2nd string in higher positions, the necessary contrast to the pedal note E, which is strongly given by the open string, cannot be properly marked. It will thus clearly appear that a complete command of the fingerboard in all positions is one of the chief technical requirements of the art of violin-playing, and that the right choice of position, on which a truly musical, tasteful, and characteristic rendering of every composition largely depends, is one of the main tests of a violinist's artistic feeling and judgment. Studies in all the usual positions are given in every good violin school. The best known are those in Baillot's 'L'art du Violon,' but they have the defect of being all written in C major.
[ P.D. ]
POSITIVE ORGAN (Fr. Positif; Ger. Positiv). Originally a stationary organ, as opposed to a portative or portable instrument used in processions. [See Organ, p. 575b.] Hence the term 'positive' came to signify a 'chamber organ'; and later still, when in a church instrument a separate manual was set aside for the accompaniment of the choir, this also was called a 'positive,' owing no doubt to the fact that it generally had much the same delicate voicing as a chamber organ, and contained about the same number and disposition of stops. By old English authors the term is generally applied to a chamber organ; the 'positive' of our church instruments being called from its functions the 'choir organ.' When placed behind the player (Ger. Rückpositiv) it was often styled a 'chair organ,' but it is difficult to say whether this name arose from a play upon the terms 'choir' and 'chair,' or from a misunderstanding as to the origin of its distinctive title. With the French the 'Clavier de positif' is our 'Choir manual.' Small portable organs were called Regals. [See Regal.]
[ J. S. ]
POSTANS, Miss. See Shaw, Mrs. Alfred.
POSTHORN. A small straight brass or copper instrument, varying in length from two to four feet, of a bore usually resembling the conical bugle more than the trumpet, played by means of a small and shallow-cupped mouthpiece. Originally intended as a signal for stage-coaches carrying mails, it has to a limited extent been adopted into light music for the production of occasional effects by exceptional players.
Its pitch varies according to length from the four-foot C to its two-foot octave. The scale consists of the ordinary open notes, commencing with the first harmonic. The fundamental sound cannot be obtained with the mouthpiece used. Five, or at most six, sounds, forming a common chord, are available, but no means exist for bridging over the gaps between them. In a four-foot instrument such as was commonly used by mail guards, the sequence would be as follows
A post-horn galop was played on this instrument by the late Mr. Kœnig. Mr. T. Harper, the eminent trumpet-player, has composed another,