If a single word can express disappointment without surprise, it would capture my feeling upon surveying the seats before this concert of 20th-century music at the Usher Hall. My heart went out to the musicians. However, upon seeing Ilan Volkov’s happy and positive demeanour and hearing the first notes, all such negativity dissolved, never to return.

A relative newcomer to Edgard Varèse, I had done some reading in the hope of enhanced enjoyment. I then noted, with a smile, in Calum MacDonald’s fine programme note, that Varèse had warned against “looking for the expression of anything in the music except the music itself.”

With some delight I found eyes and ears alerted by separate features in the opening of Varèse’s 1925 Intégrales. Volkov’s beat is as clear as I can recall seeing; a school orchestra could follow his intentions. Meanwhile, the striking rhythm and contour of the opening clarinet theme made following its progress through the small ensemble’s unusual instrumentation quite straightforward. The bright soundworld (piccolos, oboe, clarinets, horn, trumpets, trombones and four percussionists attending seventeen unpitched instruments) resulted in extraordinary colour, particularly in the work’s unmissable climactic chords. In such moments, Volkov indicated the duration of the chord with a still, right hand baton and the intensity with a shaken left fist. What I found tantalising in this ten-minute piece was the fleeting, satiety-avoiding nature of the ideas. Fine examples of such micro-tapas melodies could be heard in beautifully angular trumpet lines and in some lovely oboe note-bending by Stella McCracken. Now knowing that Intégrales forms what Calum MacDonald described as the “culminating panel of his revolutionary triptych of ensemble works” I'm now determined to seek out the preceding Hyperism and Octandre.

Like all interesting people, Varèse demonstrated contradictions. The declaration “I don't want to change one note!” did not prevent his 1921 Amériques undergoing extensive revision, resulting in the 1927 version, which was played here. Offstage brass, quarter-tone material and impressionistic passages were cut. Nevertheless, plenty remains including an impressionistic alto flute introduction.

Earlier scores having been lost in a warehouse fire, this is effectively Varèse’s Op. 1. The plural title refers not to North, Central and South Americas but more generally to possible new worlds; certainly to new soundworlds. There is, however, something of urban America in the huge score, not least a New York Fire Department Siren. Housed among the percussion, it sounded somehow less urgent than modern sirens – perhaps because it was following a conductor.

I enjoyed, in this first hearing, what sounded to me like a representation of the urban-like coexistence of unrelated rhythms. These were put over with great vigour and joie de vivre. At times I was reminded of The Rite of Spring with the caveat that the “grooves” were generally more short-lived. The complement to such counterpoint lay in arresting moments of parallel harmony. When quiet, they were haunting; when loud, they were thrilling.

Luciano Berio’s five-movement Sinfonia followed the interval. A linguistics fan, Berio simply intended the title to refer to elements sounding together, with no connection to classical symphonic form. In the inner circle of the huge orchestra sat eight members of the excellent Synergy Vocals, microphones in hand. The amplification seemed less aimed at rivalling the large orchestra than enjoying the timbres which only quiet singing can provide. If you ever have the chance to hear this piece live, you may, like me, wonder how the vocalists pitch their opening note-cluster with little obvious reference besides the opening gong. Perfect pitch or amazing memory seem the only options. Their “texts” often resided within and not above the orchestra and, in the opening movement snippets rather than lines of Claude Lévi-Strauss’ Le Cru et le Cuit (“The Raw and the Cooked”) were heard. As impressive as the singing was impeccable timing of the spoken word, while retaining natural speech rhythms.

The second movement, “O King” is an expansion of Berio’s 1967 piece in honour of Martin Luther King. The tender sustained vocal sounds (drawn from the phonemes of King’s name) are fiercely punctuated by single, offbeat sforzando notes from, amongst others, piano, amplified harpsichord, horn (difficult to see from the stalls). Volkov’s direction from the giant A2 score of this pulseless movement was impressive.

Certainly the most fun movement is the third, “In ruhig fliessender Bewegung”, a reconstruction of the similarly titled, third-of-five movement of Mahler’s “Resurrection” Symphony. Snippets from various works deflect Mahler’s triple-time elegance, perhaps the most striking being the “Dance of the Earth” from Stravinsky’s Rite of Spring.

This excellent and committed performance went down a storm with an audience who made up in vigour what it lacked in numbers.