While the conventions of improvised music most usually lead to an extended and evolving stream of consciousness, a solo piano performance by Matthew Bourne can consist of a series of short, well-defined and strikingly different pieces.

It’s indicative of an imagination sparking with possibilities yet governed by a strong sense of musicality and structure. Those qualities are absolutely showcased by Irrealis, a sequence of seven tracks improvised on a piano Bourne had ‘prepared’ for another recording with altered tuning, globs of Blu-Tak and scatterings of nuts and bolts. Following his principle of pursuing his ‘first idea’ each number takes its own shape while exploring the particular sonic distortions generated by the piano’s modifications. Thus the fluency of ‘Asaf’, which weaves a spiraling solo line around percussive clicks and looping left hand motifs, is followed by the spikiness of ‘Dusan’ with its jabbing textures and abrupt phrasing hammered to a close.

This is followed in turn by ‘Jane’, a thoughtfully melodic ballad with a dreamy atmosphere. Each piece draws a range of sounds from the instrument and uses their differences skillfully to create a multi-voiced ensemble.

The results can be surprisingly evocative: the meandering ruminations of ‘Alice’ gradually acquire a pleading urgency that steadily becomes more assertive yet finally subsides, defeated. For so short an album – it runs for just 23 minutes – Matthew Bourne conjures a wealth of musical ideas and despite all that intensity the overriding sense is one of playfulness. Here is a seriously accomplished musician gamboling in the freedom of his own imagination and delighting himself (and the listener) with what he finds there.