Quartett

Quartett, a piece of music arranged for four solo voices or instruments, in which all the parts are obligato—i.e. no one can be omitted without injuring the proper effect of the composition. A mere interchange of melody, by which the parts become in turn principal and subordinate, without any interweaving of them, does not constitute a quartett. Quartetts for stringed instruments are generally arranged for two violins, viola, and violoncello, and are in sonata form. They originated with Haydn, and were further developed by Mozart, and notably by Beethoven, who perfected the art of part-writing. Subsequent writers are Schubert, Spohr, Mendelssohn, Schumann, and Brahms. Vocal quartetts are a frequent feature in oratorios and operas, up to the time of Wagner.