Overview of later career, 1960-96

After 1961 ApIvor's music moved into its most austere stylistic phase as a result of his adoption of techniques of abstract serial composition derived from the composer Anton Webern. ApIvor usually refers to this as his post-Webern style, the first evidence of which is to be found in the Seven Pieces for Piano, Op. 30 (1960) and the Wind Quintet, Op. 31 of the same year.

It is clear that during the late 1950s ApIvor was undergoing an internal crisis as a result of Sadler's Wells rejection of Yerma and the personal problems then affecting him - specifically his recent separation and divorce from his second wife, Irene Russell (1925-2008), in 1958, and the financial problems resulting from the relinquishment of his anaesthetist's post in Trinidad. These issues had already led the composer to undertake a course of Jungian analysis in London in the early months of 1959, immediately prior to Sadler's Wells decision. According to ApIvor the culmination of these factors was the shift of stylistic emphasis:

The shock of the treatment of my work by Sadler's Wells, together with the greater interior clarity gained by my analytical experiences produced an indefinable change in me which was mirrored by a change in my musical style. This change in style was catalysed by the rapid acquaintance which I made at about this time with the greater part of the oeuvre of Webern of which I had been up to that time, largely ignorant.

The nature of the psychological change, which had its technical repercussions, is difficult to express precisely. I experienced a revulsion against compromise. I had been employing a twelve-tone technique, but in a spirit of compromise still retained the elements of thematicism, classical repetitive devices and various other procedures which were aimed at a particular sort of traditional comprehensibility. At the back of this I discerned a desire to please. But it no longer pleased me, any more than did the heavy and often noisy aggressiveness which had been a part of music since its emancipation by Beethoven. For the first time, perhaps as the result of liberating my own aggressions through analysis, I felt a positive desire towards economy of sound, the integration of silence into music, the retreat towards the miniature, and the epigrammatic, towards the non-repetitive organic growth of musical form.