Four creative eminences enlivened London’s music, none more drolly than Karlheinz Stockhausen, whose lecture, Composer and Interpreter, was delivered oddly enough at the Frieze Art Fair, a vast display of images in a temporary structure in Regent’s Park. The grandly named Guardian Auditorium, in which he appeared, seemed temporary indeed — a small black tent, with a roof cloth that made such a clattering and whistling in the wind that proceedings on the platform repeatedly came to a halt.

Stockhausen began with a frown and was not amused when his discourse on the “rushing noises” he gets woodwind players to produce was punctuated by natural magnifications of such sounds. The sound system was all wrong: no electronic magnifications for the basset-hornist Suzanne Stephens and the alto-flautist Kathinka Pasveer, Stockhausen’s long-term partners, who illustrated his remarks. But the most famous living composer, now 77, pressed on with them anyhow.

In spite of his authoritarian image, he gives a curious impression of diffidence when lecturing. With an almost childlike simplicity — no ingratiating preamble — he goes straight into the technical heart of the matter, assuming our interest in a severe analytical approach, and with little to say that does not directly apply to one of his pieces. This one was Ave, a choreographic dialogue for those two players that stems from his week-long opera-cycle Licht, recently completed after nearly 30 years’ exclusive effort.

Stockhausen spoke of how he consults the players when writing a piece to find which unusual sounds the instruments are capable of — in this case clicks, microtonal shifts, partly vocalised glissandos, as well as those rushing noises — and these he fashions into a “language”. But it is a very peculiar language, in applying, as he said, only to that particular piece. Most languages have a wider franchise. Stockhausen, though, has always had a tunnel vision of this kind, while simultaneously essaying moral dramas about the cosmos.

Bathos is the inevitable result when the sample from that universal drama proves to be no more than ladies in white jump suits (Stockhausen matched them with his dazzling, paunch-concealing white suit, set off by sharp red braces) jumping about, smiling with their eyes and sometimes squealing, as they made their newfangled woodwind gestures. In fact, the latter are not new at all: Bruno Bartolozzi discovered them years ago. And the players’ beatific expressions worryingly suggested adherents to a cult. One was dismayed to think of the composer of that electro-acoustic masterpiece, Kontakte, given next day at Old Billingsgate Market, reduced to such jejune cavortings.

Stockhausen remains a deeply seductive figure for all that. The audience’s questions seemed to restore his mood. He reacted with surprisingly good grace to the first — “Can I look at your score?”, a kind of dampening anti-question — and when prompted to explain the theology of Licht, or to tell us about Klang, his cycle-in-progress of 24 pieces, each an hour long, a Blakeian visionary stood before us.

No other living composer has anything like such a persona, and the attention one gave those others was only to their music.

Peter Maxwell Davies does have in common with Stockhausen, though, that he writes works in cycles. First it was 10 Strathclyde Concertos, now it is 10 Naxos String Quartets. The Maggini Quartet unveiled the latest, No 7, at the Wigmore Hall, and reprised No 6. The seventh is a good deal more demanding than its passingly tonal, carol-flavoured predecessor. It is a dauntingly architectonic work, finding equivalents for baroque churches by Francesco Borromini that Davies first explored as a student in Rome. All the movements are slow — the total duration a Stockhausen hour — allowing plenty of time to ponder Davies’s un- doubted compositional virtuosity. This is music in which thought is embedded rather as in metaphysical poetry, though not without (as someone said of Davies’s work) a certain presbytery dourness.

In the same hall, at a BBC lunchtime concert, the cellist Paul Watkins and his pianist brother Huw gave the London premiere of a superbly flowing Fantasie by Alexander Goehr, which is modern music at the opposite pole from Stockhausen’s cosmic wooziness: a music always at a saving distance from its classical models.

At the Barbican, the BBC Symphony Orchestra under Jiri Belohlavek opened its 75th birthday concert with the British premiere of Elliott Carter’s Réflexions. This is an 80th birthday homage to Pierre Boulez, taking his Christian name (“stone” in French) as a cue for percussion effects.

I wondered if more substance wasn’t packed into its jubilant, translucent 10 minutes than in all of Licht.