Berlin’s rise to a European music metropolis in the second half of the 18th century after the government takeover by Frederic II in 1740 was due to two circumstances: the anew involvement of music in the courtly ritual the visible characteristic of which was the formation of a royal opera house as well as the development of a multifaceted bourgeois music culture which was first institutionalised in various music playing societies and later in a public concert life.
Johann Gottlieb Janitsch born in Schweidnitz (Świdnica), Silesia on June 19th, 1708 can be regarded as a pioneer for such endeavours who, in 1738 already, created an institution with the so-called “Friday Academy” during his engagement with crown prince Frederic’s Rheinsberger Music Ensemble, which was to be continued later on in Berlin until his death. In these music playing societies, the most well-known of which was, besides Janitsch’s Academy, the “Music Practicing Circle” founded in 1749, noblemen and citizens, musically ambitioned laymen and professional musicians alike met, mainly in order to play the latest compositions by the members of the royal opera house. Sonatas for one to four instruments, symphonies, overtures and concerts by Carl Heinrich and Johann Gottlieb Graun, Carl Philipp Emanuel Bach, Christoph Nichelmann, Christoph Schaffrath, Johann Joachim Quantz, Christian Friedrich Schale, Georg Czarth as well as from Johann Gottlieb Janitsch were cultivated. These musical societies of which many testimonies of their repertoires are today located at the musical science collection of the Berlin State Library – Prussian Cultural Heritage, created, in addition to the court music, the basis for the development of instrumental music in Northern Germany in the second third of the 18th century.
[…] Only a portion of the instrumental music composed by Janitsch for his own “Friday-Academies” appears to be extant with the currently known sources to Janitsch’s compositions. With them however – in particular with the trios and quadros - there is at least an extract of that part of his works of art existent, which his contemporaries already extraordinarily highly admired. The Schwerin Court Kapellmeister Johann Wilhelm Hertel noted in his autobiography written in 1784: ...at present his quartets are still the best examples of this kind.
According to Quantz the contemporary genre standards for trios and quadros, therefore compositions for two or three instruments and basso continuo particularly exist in an equal handling of melodies of the two or three descants while avoiding filling voices on the basis of a pure four-part harmony, the use of short, invertible imitations and the fragmentation of unavoidable third and sixth sequences by means of brilliant passages.
In his compositions, Janitsch makes direct use of the traditions conveyed in compositions of trios and quadros by Pisendel, Quantz and the Graun brothers. Clinging to the genre standards of a three-part movement in Sonate da camera and in a four-part movement in the Sonate da chiesa in their outer appearance, the sonata forms also follow the harmonious conventions of the forma bipartita (with the exception of the mostly through-composed slow introduction) in their internal structure, so the respective repeated harmonious movement from the first to the fifth degree (in major movements) and the corresponding return in the second segment. However Janitsch’s trios and quadros obtain their individual character from their sensitive, detail-rich coloured and rhythmic subtle, syncopated melody creations joined with a competent contrapunctual combination of the individual voices. […] In the foreword of his three Sonate da camera as Op. I printed in 1761 in Berlin, two years before his death, Janitsch himself states wherein the difficulties of the interpretation of his chamber music lie: It is this type of composition which consists of three main= voices and a basic=voice, thereof the first arranged in a manner that they constantly copy themselves and consequently give understanding musicians the opportunity to show their skills in changing its clauses when these are repeated.