L. Van Beethoven - Große Fuge in B-flat Major (Original Score) | Klemperer, PO

Considered to be one of the most transcendental and timeless compositions of all time, Beethoven's Große originated from the finale of his 13th String Quartet. It consists of multiple double fugues and various themes that are stretched and varied upon with all possible compositional techniques, resulting in a monumental achievement; Igor Stravinsky described it as "an absolutely contemporary piece of music that will be contemporary forever".
Aside from the stunning counterpoint, Beethoven also employs daring and dissonant harmonic functions, as well as rhythmically speaking very syncopic and, if nothing else, confusing passages and melodic lines. It has often been described as incredibly difficult to play, let alone by an orchestra in which each section has to synchronise its output perfectly to convey a convincing portrayal; Klemperer succeeded with the Philharmonia Orchestra under his baton.