��a Second Part against the given Subject, in Plain Counterpoint Note against 1 Note. They sang this Part extempore : and, because it was sung by a second Voice, it was called Discantus the literal meaning of which is, a Song sung by two Voices. The Song, in this case, was not a very poetical one : but, it was fairly and logically deduced from the Cantus firmus, and therefore perfectly reasonable. Our English verb ' to des- cant ' is derived from this process of deduction, and describes it exactly ; for good Discantus con- tains nothing that is not suggested by the Cantus firmus, as in the following example, from Morley's 'Plaine and easie Introduction.'
��Canto Fermo (here treated as the Subject).
��When extempore Discant gave place to written Counterpoint, the Cantus firmus was still retained, and sung, by the Tenor, in long sustained notes, while other Voices discoursed upon it, no longer note against note, but, as Art progressed, in pas- sages of Imitation, sometimes formed from the actual notes of the Canto fermo, sometimes so contrived as to contrast with it, in pure Harmony, but with unlimited variety of Rhythm. 2 And this arrangement brought two classes of Theme into simultaneous use the Plain Chaunt basis of the whole, and the Point of Imitation the first of which was technically distinguished as the Canto fermo, while the last, in process of time, ap- proached very nearly to the true Subject of the modern Schools. The two forms are very clearly shown in Palestrina's Missa 'Ecce Sacerdos 3 magnus,' in which the long notes of the Canto fermo never fail to present themselves in one or other of the Vocal Parts, however elaborate may be the Imitations carried on in the rest.
II. By a process not uncommon in the develop- ment of specific Art-forms, the long-drawn notes of the Canto fermo, after giving birth to a more vivacious form of Subject, fell gradually into dis- use; appearing, if at all, by Diminution, or Double Diminution, in notes as short as those formerly used for Points of Imitation. In this manner, the antient Canto fermo became a Sub- ject, properly so called ; and, as a Subject, was made the groundwork of a regular Fugue. This process of development is strikingly exemplified in Palestrina's ' Missa L'Homme armeY in some of the Movements of which the quaint old Melody
1 See STRICT COUNTERPOINT.
2 See POLYPHONIA.
8 Published in Breitkopf & Hfirtel's edition, vol. X.
is treated, in Longs, and Larges, as a Canto fermo, while, in others, it is written in Semibreves, and Minims, as a Fugal Subject.*
We do not mean to imply that Palestrina in- vented this mode of treatment : but only, that he availed himself of all the good things that had been used by his predecessors. The laws of Fugue were established more than a century before his time. Not the laws of what we now call Fugue ; but those of the Real Fugue of the Middle Ages a form of Composition which differs very materially from that brought to perfection by the Great Masters of the i8th century. Real Fugue was of two kinds Limited, and Free. 5 In Limited Real Fugue, the Imitation was carried on from the beginning to the end of the Composi- tion, forming what we now call Canon. In Free Real Fugue, it was not continued beyond the duration of the Subject itself. In the former case, the Theme of the Composition was called a Guida that is, a Subject which serves as a 'Guide' to the other Parts, which imitate it, note for note, throughout. In Free Real Fugue, the Theme was called Subjectum, Propositio, or Dux : Soggetto, Proposta, or, if very short, Attacco : Fiihrer, Aufgabe, or Hauptsatz. The early Eng- lish writers called it Point ; but this word is now applied, like the Italian Attacco, to little passages of Imitation only, and the leading idea of the Fugue is simply called the Subject.
The Subject of the Real Fugue except in the Limited species was always very short, fre- quently consisting of no more than three or four notes, after the statement of which the Part was free to move in any direction it pleased. But, the treatment of these few notes was very strict. Every Interval proposed by the leading Part was answered by the same Interval in every other Part. The Answer, therefore, corresponded ex- actly with the Subject, either in the Fifth, or Fourth, above, or below ; and it was necessary that its Solmisation should also correspond with that of the Subject, in another Hexachord. 6 But, the Subject, and the Answer, had each a dis- tinguishing name. The Theme and its reply were called, in various languages, Dux and Conies, Propositio and Responsum, or Antecedens and Consequens; Proposta and Risposta, or Ante- cedente and Consequenza ; Fiihrer and Gefahrte, or Antwort ; Demande and Re'ponse. In Eng- lish, Subject and Answer ; or, more rarely, Ante- cedent and Consequent.
III. So long as the Ecclesiastical Modes re- mained in use, Real Fugue was the only species possible: but, as these were gradually replaced by our modern system of tonality, Composers invented a new kind of Fugue, formed upon a Subject the character of which differed entirely from that used by the older Masters. This form of Composition is now called Tonal Fugue. 7 It is generally described as differing from Real Fugue chiefly in the construction of the Answer. Undoubtedly, this definition disposes of its most essential characteristic. But, there are other
��See L'HOMME ARM.
See HEXACHORD ; SOLMIS.ITION.
��s See KEAL FDOUE. t See TONAL FUOUK.