In 1961 the London-born pianist John Tilbury – an associate of Cornelius Cardew and Howard Skempton – relocated to Warsaw to study with the great Polish pianist Zbigniew Drzewiecki. Musically and politically, Tilbury’s three years spent in happy exile shaped his future. Drzewiecki looked after his technique while, at night, Tilbury absorbed himself in experimental music, film and theatre, his attitudes shifting as he encountered outré figures such as the composer Tomasz Sikorski.

Sikorski’s achievements have these days been largely pushed to the margins. Often referred to as a ‘Polish minimalist’, his music has no point of reference I can hear in American process music; melodic cells might be reiterated and overlaid but each repetitive chess-move spins the music further away from its own certainty. Tilbury revives three pieces – Zertstreutes Hinausschauen (1971), Autograph (1980) and Rondo (1984) – and in each a memory-stick of off-Romantic harmony is downloaded and reconfigured. Frenzied silences puncture holes through chord sequences, while in Autograph Sikorski’s narrative ping-pongs between two harmonically polarised sorts of material: directional tremolos working against ripe, tumbling chords. The music is introverted, ominous and obsessive. Formality crumbles into a thoughtful new order. Tilbury signs off with a characteristically tender and solemn improvisation dedicated to Sikorski, each fresh sound illuminating a structure that is evolving on the fly.

‘Piano Music 1959-70’ is a reissue of an album that enjoys cult status among Cardew aficionados. The standout piece remains Volo solo (1965), conceived originally for Tilbury as an attempt to coin a new type of virtuosity. Cardew expected it to be taken at a reckless tempo so that, as he wrote, ‘the piano should seem to be breaking apart’. But the material he gives the pianist – 60 inchoate fragments interlinked by pauses – trips impetus up, the structure left with a hiccuping splendour. The three February Pieces (195961) find Cardew filtering (exorcising?) Stockhausen and Boulez; Unintended Piano Music (1970) reengages with tonality as chords are stripped of their tonal function and mysteriously placed in time.