We would do the interview in the circle. It was clearing-up time after yet another rehearsal in the Henry Wood Hall, Glasgow, and I was following a slow-moving John Cage of 78 years up the stairs as he embarassingly held doors for me and explained the tight schedule he was bound by. He has now visited the U.K. three times in one year, taking in the Huddersfield, Almeida, and Glasgow's Musica Nova festivals, all in the middle of his usual jet-setting around the world which occupies the greater part of his year. With such tight schedules and a time-consuming specialised diet, it is incredible that he grants interviews at all. His usual answer – based, as ever, in his infamous non-intention – is: ‘because people ask me to!’ Non-intentionality has been his basic aesthetic position since at least the 1950s, and as I found out, he's still finding fresh nuances there. At least when he's got the time to sit down at his desk. Why does he do it?

Cornelius Cardew's 193–page Treatise is the longest and most elaborate piece of Graphic Music ever made. Although it was intended for improvisation and realization, using as many or as few pages as required, and with no fixed rules of interpretation, the piece can be regarded as a graphic construction inspired by music – and with ‘music’, in the broadest sense, as its subject matter. It was influenced by the philosophy of Frege and Wittgenstein, and in particular the latter's exhaustive treatise Tractatus Logico-Philosophicus, which not only inspired the title but almost certainly the composer's economical approach to this endeavour and the rigorous development of his material. It was composed from 1963 to 67.

In the early 1920s and 30s a strange electronic instrument found its way from Russia into some of the more fashionable ballrooms, night clubs, and concert halls in Europe and America. This exotic new invention, called the ‘theremin’ or ‘thereminvox’, caused a considerable stir. Part of the interest was its unusual sound (like a musical saw mated with a light soprano), but its most dramatic feature was that the performer never actually touched the instrument. He or she simply waved graceful hands near the two antennae (one set vertically, the other looped horizontally) to coax out seamless, melifluous melodies. The proximity of the right hand to the vertical antenna changed the ultrasonic electromagnetic field, thus changing the pitch over about a six-octave range. The left hand (or sometimes a foot pedal) controlled the volume. By gently shaking the right hand at the antenna a vibrato could be achieved, giving performances a little more musical (not to mention choreographic) interest. Fashionable women dressed in long gowns seemed to be favourite photographic subjects of the period as performers, as well as the inventor himself, poised ‘playing the rods’ in full dress tails, arms outstretched like a great conductor–or perhaps sorcerer.

Gradually the picture of Russian music in our century begins to fill out. The modernists of 70 or 80 years ago like Mossolov and Roslavets are beginning to make the nervous transition from text-book to performance. The constant revaluation of Shostakovich and Stravinsky makes for a couple of flourishing industries. And some living composers like Schnittke and Gubaidulina have produced works which seem almost to have been accepted as part of the repertoire

Heitor Villa-Lobos's musical output is very comprehensive. Nevertheless, he thought it useful or necessary, at some later stage, to incorporate certain pieces – in their original form or in transcription – into other compositions, apparently for lack of time to write a completely new work, or sheer laziness. Or, he found delight in teasing his listeners, friends and admirers, unless they discovered his hoax. The Brazilian composer-conductor Walter Burle-Marx (b. 1902), in a letter to me of 31 May 1981 from Caracas, Venezuela (and reproduced here by his kind permission), commented on this characteristic of Villa-Lobos

A typical example of Villa-Lobos's temperament and way of thinking concerns the Bachianas Brasileiras # 5.1 did the U.S premiere in New York at the World's Fair on May 4th, 1939 with the New York Philharmonic and Bidú Sayão, using the manuscript of Villa-Lobos. Later on, when I saw the manuscript again, there was a repeat sign on the first introductory measure in 5/4. I asked him why he did that and he replied that he felt that the introduction was too short. I asked why he didn't compose two different measures – he who had so much imagination – and he smiled and said: ‘To tell the truth, I felt lazy’. This was one of his faults; once a work was finished, he very rarely went back to polish it much less to change it.