“A night of new music on the harpsichord is a tall order,” Mahan Esfahani told his Barbican audience. Not that it felt like it in the least. If there was an intimidation factor attached to this night of experimental music with electronics, mixing classics by Luciano Berio and John Cage with premieres, then it was quickly ushered from the hall by Esfahani’s generosity and warmth.

The Faroese composer Sunleif Ramussen opened the programme, with the world premiere of Quadroforone no.1, which juxtaposes live instruments against recordings of themselves. The layering of textures and tempi produced a landscape from which Esfahani’s live performance would recede and emerge, sometimes, as in the Nocturne section, as lyrical protagonist, and sometimes as the vehicle for recursive, percussive repeated patterns.

Berio’s Rounds from 1965 comes from the composer’s attempts to shed conventional practices in musical notation, creating something more musically capricious; the title describes the way the performer should turn the score upside down halfway through, creating a literal musical inversion of the first section, before righting it again to make a faster, bristling coda out of the original material. In Esfahani’s hands it is crisp and flighty from the outset, with a denser and more emphatic middle. Though the skittering runs and clashes are echt-modernism, there’s also a touch of the archaic: the structure resembles that of a Baroque aria, with roughly A-B-A form and circumscribed turnings of the raw material.

Closing out the first half was Miroslav Srnka’s Triggering, a piece in eight short movements with a trickster-like humour. Srnka looks at the harpsichord and sees an instrument with an apparently banal mechanism – on or off, plucked or un-plucked – which the music then takes apart. He does this through witty riffs that defamiliarise the sounds of the harpsichord, as in the juddering of movement five (“My Mom Just Got the Only Sewing Machine Available Back then and Learns”) or the comic glissandi of “The Last Tennis Match With My Grandfather”.

This music, a kind of Baroque Futurism, showcases Esfahan’s unerring virtuosity. But there is a spiritual and emotional range too. The final movement, “Does God Shoot his own Particles?”, saw Esfahani (and his page-turner) move to a second harpsichord to use EBows (a sort of electric guitar pickup) over its strings, was ever so delicately pushing the keys to find that indistinct point where they do something other than pluck. This was desolate and cosmic, ending in total darkness, the harpsichord sounding sometimes like a clarinet or the rubbed rim of a wine glass.

And then Mozart. Well, not quite. Solo VII from Cage’s HPSCHD has only the instruction that the musician “practice/and or perform any composition(s) by Mozart”. Esfahani brought the Fantasia in D minor, K.397, and a pencil. Its other parameters – the duration and shape of the live electronics, or starting points – were determined there and then using a digital version of the I-Ching, the ancient Chinese Book of Changes that Cage used to introduce aleatoric procedures to his compositions.

Introducing the piece, Esfahani was keen that Cage’s music isn’t taken as a kind of joke, which is quite right. The synthesised instrumental sounds and effects that bleeped around whirred around the four corners of the room. At times this would draw out the alien, clanging qualities of the harpsichord’s sonorities; at others it was like hearing Mozart on the bridge of the starship Enterprise. It’s a fascinating exploration of what it means to ‘practise’ music in front of an audience, and the strange relationship to ideas of public and private that musicians must have in their lives. But the piece’s liveliness and unpredictability are what stand out and make it so engaging.

Closing out the programme was more new music, this time from 33-year old Anahita Abbasi, her 2018 Intertwined Distances receiving its UK premiere. The piece is constructed out of reprocessed harpsichord sounds from recordings of the work that Esfahani developed with the composer: as he reminded us, much of the piece has already been performed elsewhere.

This ghostly, belated character is commensurate with the music: the electronics evoke bells, sea swells, wind, a Russian Orthodox choir; deep groaning and creaking sounds combine with the curved wooden panelling of the Milton Court performance space to create the impression of being inside some great haunted ship. The acoustic space of the music contracts and expands constantly, as does its sense of pace and change, with dazzling passages redolent of Scarlatti’s great glittering toccatas.

Special mention should go to Sean Norris, a student at the Guildhall who didn’t receive a credit in the programme, and was responsible for coordinating the electronics in the performance: his partnership with Esfahani was special indeed.

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