estimates that Sorabji's extant musical output, which he describes as "[perhaps] the most extensive of any twentieth-century composer", may occupy up to 160 hours in performance. Sorabji's harmonic language often combines tonal and atonal elements, frequently uses triadic harmonies and bitonal combinations, and it does not avoid tonal references. It also reflects his fondness for tritone and semitone relationships. Despite the use of harmonies traditionally considered harsh, it has been remarked that his writing rarely contains the tension that is associated with very dissonant music. Sorabji achieved this in part by using widely spaced chords rooted in triadic harmonies and pedal points in the low registers, which act as sound cushions and soften dissonances in the upper voices. In bitonal passages, melodies may be consonant within a harmonic area, but not with those from the other one. Sorabji uses non-functional harmony, in which no key or bitonal relationship is allowed to become established. This lends flexibility to his harmonic language and helps justify the superimposition of semitonally opposed harmonies. Creative process and notation Because of Sorabji's sense of privacy, little is known about his compositional process. According to early accounts by Warlock, he composed off the cuff and did not revise his work. This claim is generally regarded as dubious and contradicts statements made by Sorabji himself (as well as some of his musical manuscripts). In the 1950s, Sorabji stated that he would conceive the general outline of a work in advance and long before the thematic material. A few sketches survive; crossed-out passages are mostly found in his early works. Some have claimed that Sorabji used yoga to gather "creative energies", when in fact it helped him regulate his thoughts and achieve self-discipline. He found composition enervating and often completed works with headaches and experiencing sleepless nights afterwards. The unusual features of Sorabji's music and the "ban" resulted in idiosyncrasies in his notation: a shortage of interpretative directions, the relative absence of time signatures (except in his chamber and orchestral works) and the non-systematic use of bar lines. He wrote extremely quickly, and there are many ambiguities in his musical autographs, which has prompted comparisons with his other characteristics. Hinton suggested a link between them and Sorabji's speech, and said that "[Sorabji] invariably spoke at a speed almost too great for intelligibility", while Stevenson remarked, "One sentence could embrace two or three languages." Sorabji's handwriting, particularly after he began