It was lucky for the development of instrumentation (as in all branches of music during the change from polyphonic to formal design) that whenever the texture is not polyphonic the natural place for melody is on the surface: in other words, when the accompaniment is simple the tune is generally on the top. Haydn, when he was not tempted by the resources of an instrument so complete in itself as the pianoforte, soon learnt to write artistically perfect string quartets in which the first violin, though overwhelmingly the most important part, is nevertheless in perfect balance with the other members of the scheme, inasmuch as they contribute exactly what their pitch and the little polyphonic elaboration admissible by the style will enable them to give.
Thus there were no string-quartets, before Haydn - at least none that can be distinguished from: symphonies for string-band.
On this differentiation of styles rests the whole aesthetics of chamber-music; but the subject is very subtle, and there is much, as for example in Schubert's quartets and his C major quintet, that is inspired by orchestral ideas without in the least vitiating the chamber-music style; though, judged by its appearance on paper, it seems as unorthodox as the notoriously orchestral beginnings of Mendelssohn's quartet in D and quintet in B.
Classical and modern chamber-music in the sonata style consists mainly of string-quartets for 2 violins, viola and violoncello; string-trios (rare, because very difficult to write sonorously); pianoforte-trios (pianoforte, violin and violoncello); pianoforte-quartets (pianoforte with string-trio); pianoforte-quintets (pianoforte with string-quartet); string-quintets (with 2 violas, very rarely with 2 violoncellos), and (in two important cases by Brahms) stringsextets.
At the beginning of the 19th century a revival of the popularity of this instrument took place, and quartets were played on four sets of pipes of different sizes and pitch.
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