��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 Bb Symphony. The canzonetta in Mendelssohn's Quartet in Eb, 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. Paga- nini 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 (6) and (c).
���(The notes marked * to be played pizzicato with the left hand.)
A natural harmonic note, when played pizzi- cato, 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. [P-D-]
PLAGAL CADENCE is the form in which the final Tonic chord is preceded by Subdominant Harmony. [See CADENCE.]
PLAGAL MODES (Lat. Modi plagales; Gr. ir\ayi ot ^x ' 1 ' Germ. Plagaltone, Seitentone, Nebentone). When the Plain Chaunt Melodies were first reduced to systematic order, tradi- tionally by S. Ambrose, Bishop of Milan, to- wards 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 Authen- tic Modes,' were named and numbered, in imi- tation of certain still more antient Greek tonal- ities from which they were more or less directly
1 In contradistinction to the xvpioi >5x 'j or Authentic Modes.
derived. Thus, the first, having D for its Final, was called ' Authentus primus,' or, the ' Dorian Mode'; the second, with E for its Final, 'Au- thentus deuterus,' or, the ' Phrygian Mode* ; the third, with F for its Final, 'Authentus tritus,' or, the 'Lydian 2 Mode'; the fourth, with G for its Final, 'Authentus tetrardus,' or, the 'Mixolydian 3 Mode.' And the compass of these Modes was sufficiently expended to include that of all the Ecclesiastical Melodies then in com- mon 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 -n-\a.yios, oblique, borrowed). These supplemental Scales involved no new combinations of Tones and Semi- tones. 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 under- stood, if we bear in mind that every Authen- tic 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 ECCLESIAS- TICAL.] Thus, the First, or Dorian Mode, con- sists 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 :
��tr ._- ^ =
Authentic Form. I final.
�� ��Plagal Form.
��2 The Hyperphryglan of Martianus Capella. Called, also, by those who contend for the purely Greek origin of the Ecclesiastical Modes, the .fliollan ; the true Greek Lydian being a whole Tone higher than, the Phrygian, and not, as in this case, a Semitone.
3 The Hyperlydian of Capella.