The ultra-cerebral stereotype of the New Complexity often feels like a bit of a chimera. Blame all those images of stem-and-stave-blackened pages and La terre est un homme’s score extending beyond all reason. Sure, there’s that, but the music can also be as playful as it is serious, as sparse as it is dense, as imaginatively rich as it is cerebral.

As much is clear from Red Note Ensemble’s double release of premiere recordings of two recent works it commissioned from James Dillon. The newish pieces, Carnival and Tanz/haus, are each over 40 minutes long; both feature smatterings of electronics and are opposites in tone and mood, combining as a useful gateway to Dillon’s brilliant oeuvre. They show different aspects of New Complexity music, the one low-key, the other more strident.

Carnival is in 15 movements that explore different combinations of six instruments (a Pierrot ensemble with piano replaced by synthesiser and added percussion). As often with modernist music, we get several allusions at once, with some of the short movements’ titles being taken from Finnegans Wake and, more saliently, the overall work title nodding to Schumann’s similarly named solo piano work. The Schumann takes precedence because, in Carnival, Dillon is at his most playful and puckish.

There’s wry humour in the stop-start texture of ‘waiting for spring’: a minor triad on piano keeps trying to get going yet interrupts itself with a tritone, before eventually the other instruments, flute, clarinet and cello, burst in. ‘three-ring circus’ is reminiscent of Donatoni in its unison and heterophonic lines running up and down, then swelling, quietening, trilling. ‘rope dance’ for clarinet and echoing electronics is sprightly, while ‘larch’ for violin and marimba is a chirpy atonal avian dance.

Dillon, who has latterly worked at IRCAM, doesn’t over-egg the electronics, knowing that a light touch is more effective than pell-mell indulgence. In ‘snow alley’ for violin, cello and flute, static drones are interspersed like snow flurries with fast contrary motion interpolations. ‘turning tricks’ uses a tremolo effect to engaging effect over a resonating gong. The full ensemble of ‘phosphorus’ closes the disc over swelling synthesiser chords.

As John Fallas informs us in his booklet notes, titles for Dillon are like carnival masks, both revealing and concealing. The aforementioned ‘rope dance’ for clarinet and electronics plumps for straightforward agreement between title and music, gambolling fast clarinet flourishes reminding us of circus trickery. On the other hand, ‘merry go raum’ – whose title suggests something, well, merry – is a deeply felt, intense piece of prolonged Scelsi-esque tones gradually increasing in intensity. There is the odd solo, as with ‘stage décor’ for flute, like a player under a spotlight on the proscenium delivering a monologue.

If the second disc, Tanz/haus, is slightly more demanding, that’s the outward effect of its artistic depth – it’s music that rewards repeated listens, and the work secured Dillon his fifth Royal Philharmonic Society Award. Formally, the listener is helped by Tanz/haus being based around polarities. Stasis and movement is the recurring opposition, with each containing the germ of the other. Amid the atonal polyphony and glowing harmonic clusters there are hints of tonal elements.

Tanz/haus opens with cymbals and gongs and the looping voice of Martin Heidegger talking about technology. Accordion and electric guitar are prominent here in the early stages. The music has the quality of a slow drift, like coloured inks gradually, expansively staining a manuscript page. Trills and pizzicato alternate, as do swelling pedal tones and pointillist notes, overbowed violin and humming accordion, deep rumbling percussion and high shrieking clarinet. All gratitude to Red Note Ensemble, who, in high-definition audio, perform the commissioned works with razor precision.