instance of effective orchestral pizzicato occurs in the scherzo of Beethoven's C minor Symphony, just before the entry of the finale, and also in the adagio of the same master's B♭ Symphony. The canzonetta in Mendelssohn's Quartet in E♭, op. 12, affords an illustration of its use in chamber-music. In solo-playing a distinction is made between the pizzicato executed with the left, and that with the right hand. The former one is more frequently used, but not so much in classical as in brilliant modern pieces. Paganini made an extensive use of it, either by playing a pizzicato accompaniment to a tune played with the bow (a), or in quick passages with arco notes interspersed (b) and (c).
(The notes marked * to be played pizzicato with the left hand.)
A natural harmonic note, when played pizzicato, produces an effect very similar to that of a note on the harp. Sterndale Bennett makes use of it in the serenade of his Chamber-Trio. There is, however, hardly another instance of this effect to be found. [App. p.749 "Add that early instances of the use of this effect are to be found in Handel's 'Agrippina,' 'Pastor Fido,' 'Terpsichore,' and in an air by Hasse, written for Mingotti in 1748."]
[ P. D. ]
PLAGAL CADENCE is the form in which the final Tonic chord is preceded by Subdominant Harmony. [See Cadence.]
[ C. H. H. P. ]
PLAGAL MODES (Lat. Modi plagales; Gr. πλάγοι ἧχοι; Germ. Plagaltöne, Seitentöne, Nebentöne). When the Plain Chaunt Melodies were first reduced to systematic order, traditionally by S. Ambrose, Bishop of Milan, towards the close of the 4th century, four Modes only were in use—those beginning and ending on the notes now called D, E, F, and G. These venerable Scales, known as the 'Four Authentic Modes,' were named and numbered, in imitation of certain still more antient Greek tonalities from which they were more or less directly derived. Thus, the first, having D for its Final, was called 'Authentus primus,' or, the 'Dorian Mode'; the second, with E for its Final, 'Authentus deuterus,' or, the 'Phrygian Mode'; the third, with F for its Final, 'Authentus tritus,' or, the 'Lydian Mode'; the fourth, with G for its Final, 'Authentus tetrardus,' or, the 'Mixolydian Mode.' And the compass of these Modes was sufficiently expended to include that of all the Ecclesiastical Melodies then in common use.
Some two hundred years later—if tradition may be trusted—S. Gregory added to these Modes four others, directly derived from them, and hence called Plagal Modes (from πλάγιος, oblique, borrowed). These supplemental Scales involved no new combinations of Tones and Semitones. They were simply formed by enlarging the compass of the Authentic Modes, downwards, to the extent of a Perfect Fourth, the three upper notes being removed, in order that the compass of the Scale might still be comprised within the limits of an Octave, while the Final remained unchanged. This will be readily understood, if we bear in mind that every Authentic Scale consists of a Perfect Fifth, and a Perfect Fourth, the Fourth being placed above the Fifth, and beginning on the note on which the Fifth ends. [See Modes, The Ecclesiastical.] Thus, the First, or Dorian Mode, consists of a Fifth, D, E, F, G, A, surmounted by a Fourth, A, B, C, D. Now, if we add an A, B, and C, beneath the lower D, and compensate for this extension by removing the upper B, C, and D, we shall produce a Scale consisting of a Perfect Fourth, A, B, C, D, surmounted by a Perfect Fifth, D, E, F, G, A; and this Scale will be the Plagal form of the Dorian Mode, and will serve as the type of all similar derivations, as may be seen from the following examples:—
- In contradistinction to the κυριοι ἧχοι, or Authentic Modes.
- The Hyperphryglan of Martianus Capella. Called, also, by those who contend for the purely Greek origin of the Ecclesiastical Modes, the Æolian; the true Greek Lydian being a whole Tone higher than, the Phrygian, and not, as in this case, a Semitone.
- The Hyperlydian of Capella.