Confronted by this recording, I need to begin by failing to define lightness in music. Concretely, of course – statistically, aurally – it has something to do with timbre (airy, crystalline) and register (high), and probably also with tonality- or consonance-adjacent harmony: the sorts of things that make poets of lightness out of Salvatore Sciarrino, Niccolò Castiglioni and Gérard Pesson. This is a kind of lightness specific to music, a sensory lightness.

But there is also a conceptual sort of lightness, a broader aesthetic condition of the sort Italo Calvino, in his Six Memos for the Next Millennium, pinpoints and traces back to Lucretius. This more fundamental lightness has to do with a sense of transcendence through mutability, of an acknowledgement and reflection of fundamental emptiness and instability. Not that things are not what they seem, but that they are only what they seem and that that seemingness is contingent and its conditions unfixable. Calvino seems to identify heaviness, weightiness, with certainty: with stability, with questions answered – and, perhaps, with fixed definitions.

It is this sort of lightness, or the opposite of this sort of heaviness, that we find in the work of the two composers active on this record: Stefano Gervasoni, naturally, but also Robert Schumann, who hovers here, sometimes in the background and sometimes – in Altra voce: omaggio a Robert Schumann, for piano and electronics (and an interloping mezzo-soprano) – blindingly in the foreground. This is a lightness of indeterminacy, of holding things open, of gazing outwards at an unknown object; and the project of Altra voce seems (seems!) to be the recuperation of this indeterminacy in Schumann's piano and chamber music.

Concretely, Altra voce comprises a suite of five pieces for a transducer-enhanced piano (and, in one instance, mezzo-soprano Monica Bacelli). Each is essentially an arrangement of a small work of Schumann's, from the obscure (the last of the 12 Vierhändige Klavierstücke für kleine und große Kinder, op. 85) to the immediately familiar (Vogel als Prophet), with the source subtly or dramatically supplemented, timbres alienated and denatured, keyboard sounds electronically detuned, implied shadows brought to the surface. In the second piece, Sirenenstimme, based on one of the op. 88 Fantaisiestücke for piano trio, the strings sound like nothing so much as theremins recorded long ago on a wax cylinder; in the last, Alba mentore, the opening piece of the Gesänge der Frühe is accompanied and inflected by its own dissonant, frozen resonances, which take over in a long post-Schumannian coda. Bacelli contributes an invented (‘implied’) melody to the Verrufene Stelle movement from Waldszenen, setting as a text the poetic epigraph with which Schumann opens the piece. And so on. It is difficult to know whether to call this quixotic project a success, and that difficulty is precisely a symptom of what I will insist on calling the project's lightness. But it is easy to admit that it is memorable, haunting, that it calls one back and that – even if it does not always convey in itself the aesthetic, Lucretian lightness of Schumann's compositional thought – it is no bad thing to be reminded that it is there, encrusted under centuries of familiarity.

In his booklet essay, Gervasoni claims a connection to Schumann in the next cycle as well, Fu verso o forse fu inverno: sei liriche de Lorenzo Calogero, for mezzo-soprano and piano with electronics (transducers again, alongside six channels of audio through spatialised speakers). His assertion of an homage is enough to call it into being, of course, but does not necessarily make it easy to locate. There is no Schumann on the surface here. Certainly, these songs are Schumannian in the sense that many songs after Schumann are Schumannian – that sense being an acceptance of the fragmentation and incompletion inherent in the nature of the form and its use towards a sort of psychological realism, an inheritance from Schumann's taking seriously the destructive possibilities of the aesthetics of German Romantic literature.

The sense of, as I put it above, ‘gazing outwards at an unknown object’ takes concrete expression in a variety of ways throughout Fu verso. The material is constantly bursting its bounds. What could be, and would succeed on its own terms as, a thoroughly worked-out song cycle for voice and piano – the harmonies lovely, the modes of interaction and dramaturgy convincing and varied, the tone of both Bacelli's voice and Aldo Orvieto's piano wonderfully flexible – is continually dogged around the edges by excess via the electronic component: whispering voices, echoing spectral sopranos, harmonies disconcertingly held and artificially extended for what seems like ages in a sudden refutation of the very idea of pianism, sudden sounds of rain.

At the end of the disc comes Muro di canti, at over 20 minutes by far the longest uninterrupted work here. Originally conceived as part of an installation by the visual artist Giuseppe Caccavale, this purely acousmatic piece is centred around two fragmented, re-layered and processed recitations (Bacelli again, declaiming, whispering, mumbling) of Giacomo Leopardi's famous ‘Canto notturno di un pastore errante dell'Asia’, with additional texts (marginalia? commentary?) from four contemporary poets. This whole discursive universe is accompanied by carpets of sound in which the original installation's construction and set-up feature prominently: hands alongside words.

On its own, divorced from its context on this disc and from its original surroundings, Muro di canti is clearly well paced and thoughtfully constructed but not particularly memorable in its particulars. And I cannot speak to its function in the context of Caccavale's installation, though I could imagine it being shatteringly effective. I found myself listening to it, though, as a postlude to the rest of this recording, as a sort of afterimage or resonance-at-a-distance of Altra voce and Fu verso o forse fu inverno. In this sense, Muro di canti forms the evaporative end state of a languorous process of dissolution and uncertainty that begins at the record's opening with the enigmatic little moment of preluding that Gervasoni places before the first Schumann arrangement of Altra voce.

Three works, then, and three modes of openness: three lightnesses, or maybe only one. Within this larger frame, though, while Muro di canti is the most ambitious work here and Fu verso o forse fu inverno the most musically sophisticated in a compositional sense, it is Altra voce, the ghostly set of almost-transcriptions, that has stuck with me over repeated listenings. There really is something light about it, its touch, the gentleness of its reframing even when the devices employed are dramatic: it would not surprise me if Calvino and Schumann were nonplussed at first, and then, in retrospect, secretly pleased.