A festival of contemporary music now in its second year called Principal Sound – its name taken from Feldman’s only organ work – explores the substance of sound itself, with works by Feldman and Luigi Nono as a pivot.

The final concert, by Explore Ensemble and the vocal group Exaudi, mixed ancient and modern: from Machaut’s courtly promise of spring love – Rose, liz, printemps, verdure – to Wolfgang Rihm, Rebecca Saunders, John Croft and a world premiere, Uncertain for 8 Voices, by the American composer Linda Catlin Smith. Hushed, evocative and hinting at louder dissonances that never materialise, this was a setting of fragments from Virginia Woolf’s The Years.

At Kings Place, this year’s unwrapped theme, Time, marches on. A specially devised new work by the percussionist Manu Delago called Inside a Human Clocktook a literal and spatial approach to chronometry. Starting exactly on the hour, a mixed ensemble of instruments and voices – appropriately a dozen musicians in all – mimicked the internal mechanisms and outward progress of a clock, marking the seconds and minutes of a single hour via ticks, tocks, chimes and whirrs, as well as a lugubriously metrical and oddly catchy account of Rock Around the Clock.

The audience sat in the middle, some splayed on beanbags, others upright, alert to the minute oscillations of each player, who processed around the circumference, improvising according to Delago’s preconceived framework. His own delicate playing of the hang stole the show. This drum-like instrument, shaped like a flying saucer, inspired by steel pans and played with the fingers, is a 21st-century invention, its sympathetic vibrations and strange acoustical properties as much a fascination to physicists as to musicians. It was invented by the Swiss, who might think they’ve had it up to here with clocks. It may explain why this enchanting curiosity ended bang on time, but let’s credit the punctual musicians, timekeepers par excellence.