Not a spare seat to be had when the great Hungarian modernist György Kurtág and his wife Márta perform at the piano. Compared to extravagant composer-pianists such as Liszt or the forearm-bashing Henry Cowell, the Kurtágs’ dedication to the gnomic and pointillist might make them seem tame. But to hear them in selections from György’s epic miniature collection Játékok (Games) is still a magical experience. Or should be.

Nothing could have held more promise than their warm-up dip into Bartók’s Mikrokosmos and transcripted Bach. Husband and wife sat side by side at their upright piano with the mute pedal depressed, conjuring the gentlest, most subtly penetrating, four-handed counterpoint.

Microphones, supervised by György Jr, their electro-acoustic son, deepened the muffled reverberations. Imagine music played under water or from behind a hundred handkerchiefs. Brilliant, for a while. Trouble is, when the dynamic range is so restricted, the ears become extra sensitive. A digital watch. A police siren outside. We suffered them all, and each disrupted concentration on succeeding pieces. A brief chain of awkward chords; gnarled clusters; 18 seconds of smudges: sometimes Kurtág the composer offers nothing more. Rapture finally bounced back with the moving Bach Actus tragicus transcription, stripped down to the peace that passes understanding; but overall the 24-minute selection needed extra meat.

The glories and pitfalls of Kurtág’s miniature style were equally audible in the UK premiere of his new half-hour Hipartita — named after its classical form, the partita, and the first syllable of Hiromi Kikuchi, its wonderful performer. Though the manuscript sheets were spread out across ten stands, she played with a depth of feeling only possible when the notes are lodged in the memory and heart. As often with Kurtág the tiniest pieces seemed private musings, of baffling significance. The joy came when the music opened out, and he gave himself wings.