FUGUE. - A form of composition that summarizes the principal criteria of the development of musical thought and the principal procedures of so-called "imitative" counterpoint, that is, based on the reproduction, in various voices, of a given thematic element.
The fugue is constructed in that ternary form which is also widely applied to symphonic art in the three phases presentation, development and recapitulation: the two lateral pillars support and condition the central one. In the first section of the fugue (exposition) the fundamental theme (subject) is presented successively by the different voices: and the secondary theme (countersubject) is interwoven with it. The latter is combined with the former according to the rules of invertible counterpoint, so that the two simultaneous themes may stand one above or equally below the other.
The complete presentation of the subject and countersubject in all the voices is followed by the so-called divertimenti, episodes in which the thematic elements are developed and which are inserted between the statements of the subject in other keys.
The final part is the most interesting and the most learned, on account of the close interlockings (stretti), the canons (prolonged imitations), the possible episodes in triple counterpoint, the augmentations (when the rhythmic values of a theme are proportionally increased) and the other possible contrapuntal procedures, more or less ingenious and far-fetched, culminating in strettismo and in the final pedal, which is a prolonged note in the bass, over which new thematic combinations are superimposed.
To this general scheme the composition of a fugue conforms with greater or lesser rigor according to whether it is a school fugue, a fugato, or a fugue as part of a symphonic movement, or again a personal construction inspired by the fugue. The fugato is of two principal types: 1) exposition followed by stretti; 2) the section that follows the exposition is composed with ample freedom of procedures, that is, without being subject to the precise rules that instead hold for the scholastic fugue. As a wonderful model of a fugue, inspired by highly artistic criteria and with personal meaning, let us recall the one that closes op. 110 of Beethoven (they are in reality two fugatos, of which the second is on the inverted theme of the first; and such inversion has value in the particular and general meaning of this celebrated sonata).
As for its historical origins, these are linked, on the one hand, to the Flemish polyphony of the second half of the fifteenth century, and on the other to the first instrumental forms, such as the ricercare; and these origins are determined, substantially, by imitation at the 5th. In the Istituzioni armoniche of G. Zarlino (Venice 1358) there is a complete enunciation of the structure of the fugue, conceived as a monothematic form. Extensive use of fugal technique is found in the German organists of the seventeenth century, with whom the fugato is also interwoven with the chorale. But even earlier, that is, in a Ricercare di X tono by G. Gabrieli (1595), one can detect one of the very first examples (if not the absolute first: let us bear in mind that the "firsts" in the history of music are always uncertain) of a fugue with divertimenti.
It is superfluous to recall that all the great musicians cultivated this form, each with characteristics of his own. Thus, for example, Handel gives the fugue an amplitude and a majesty all his own. The Mass in B minor of J. S. Bach offers unsurpassable models of fugue for chorus and orchestra. But the immense work of Bach is entirely based on fugal technique, which never prevented that supreme master from reaching the heights of power of expression and poetic evocation through sounds.
Edgardo Carducci-Agustini