In the contents and cohesive context of the chamber works of Johannes Brahms (1833-1897), the two Sextets for two violins, two violas and two cellos (op.18 and op.36) form a compositional diptych that expresses, clarifies and consolidates the link with a classical tradition that is well assimilated in forms and constructs, but enriched by an extensive and expressive thematic lexicon, by an original, and in certain senses, innovative conception of the variation of development, and by functional and systematic harmonic substrates.
Composed between 1858 and 1865, these two works configure a sound space that is wholly unusual (the only significant precedent might be found in the Sextet op.140 by Luis Spohr, which dates to 1850), which departs from the four-dimensional monochrome of the string quartet and makes possible, perhaps in a spatial optics of an unconscious pianistic derivation, the aggregation and alternation of various and dialectic combinations of instruments. Further, the consequent dilatation of form appears to occur, or better, to become concrete, in the gradual acquisition of symphonism, the fruit of unceasing preparatory work (from to the Serenades op.11 and op.16, and from the Concerto in E minor for piano and orchestra op.15, to the Variations of a theme by Haydn op.56a), but also and above all matured thanks to the variegated and parallel process of chamber composition. This is, therefore, a kind of slow genesis, but in the accession of works conceived by an undepleted creative genius, capable of moulding ideas and concepts that, in the furrows of tradition, are such in inventio and in tractus (understood as ideation and development) as to express the absolute in music: in an aesthetic context that sees the uncontesteddominanceofmatteroverform,orattheveryleast,the need to place a literary derivation or justification before language (from Berlioz to Liszt, from Wagner to the composers of the national schools), pure music, extraneous to the representation of the sensible world, perhaps finds in Brahms the sole composer capable of realising an anti-Romantic formalism, alien to the representation and expression of sentiments and emotions, non-semantic and inexpressive, but nevertheless conjoined to the supreme beauty of motivic formulations and with the architectonic and structural variations of development already mentioned. Yet, surpassing the hesitations of Hanslick, his thematic statements and related harmonic and instrumental treatment often arouse in the listener multiple sensations and suggestions, though of a different nature, strongly evocative of Romantic ideals, in virtue of passionate phraseologies, lingering passages and tormented melodic elaborations.