Opus clavicembalisticum

Opus clavicembalisticum is a work for solo piano, notable for its length and difficulty, composed by Kaikhosru Shapurji Sorabji and completed on 25 June 1930.

However, some works conceived by New Complexity, modernist and avant-garde composers, along with Sorabji himself, were even more demanding; it is in this particular area that Opus clavicembalisticum is highly regarded and primarily receives its notoriety.

Opus clavicembalisticum has twelve movements of hugely varying dimensions: from a three-minute-long cadenza to an hour-long interlude, containing a toccata, adagio, and passacaglia (with 81 variations).

[4] In a letter upon completion of the massive work on 25 June 1930,[2] Sorabji wrote to a friend of his: With a wracking head and literally my whole body shaking as with ague I write this and tell you I have just this afternoon early finished Clavicembalisticum...

The closing 4 pages are so cataclysmic and catastrophic as anything I've ever done—the harmony bites like nitric acid—the counterpoint grinds like the mills of God... (underneath he quotes the last chord of the work, with "I am the Spirit that denies!