One of the most important early chamber works by Jean Sibelius (1865-1957) is the STRING QUARTET IN B-FLAT MAJOR, OP. 4. Composed in 1889 and 1890, it is the only one of these works, besides two short pieces for violin and piano which eventually faced revision, to which an opus number is attached. The quartet premiered on October 13, 1890 at the Helsinki Music Institute. In February 1894, Sibelius arranged the third movement as a PRESTO for string orchestra, adding a double bass part, but leaving the other parts unaltered. The first performance took place on February 17, 1894 in Turku, the composer directing the Orchestra of the Turku Musical Society. Instrumentation: String Orchestra (8-8-5-5-5 in set).