By the time I started writing the Piano Sonata in 1998 I had been thinking for a while about the possibilities of making works out of two separate parts which would balance one another. In order for this to be effective the two parts would have to be more or less self-sufficient, and have their own internal balance: in fact the first movement has been performed several times as a piece in its own right; the second movement has its own material until near the end when a sort of coda mixes the material from the two movements (albeit inconclusively).
People usually want to know about the movements’ subtitles: well, these are much less important or relevant to me than they were when I wrote the piece but what I had in mind was that the first movement (Variation) was at the same time a set of fairly clearly delineated variations, and a progressive exploration, through variation, of the material of the opening; the second movement (Erosion/Glacial) has two distinct ideas, one of which is made of rather dense but quiet chords, and is gradually “eroded” by the second idea, which has much clearer polyphonic lines spread out across the different registers of the piano (and is “glacial” in character).
As for the overall form of the work – two movements of approximately equal length and starkly contrasting character and colour – there is an underlying model for this shape in my main extra-musical passion: hill-walking. The somewhat violent first movement evokes struggle, so often symbolised as the climbing of a mountain. And indeed it was in my mind to find a musical expression of the sensation of climbing among the complex topography of my favourite hills in the Cuillin of Skye. So certain ideas come into view, are obscured and reappear in a different form, until finally they appear in their very closest and most imposing guise.
The more reflective second movement is to some extent an expression of the calm and serenity I feel on having gained the summit: I had the impression on hearing early performances of the piece of watching an endless and impossibly slow helicopter-shot receding upwards from a summit so that other views gradually come into the frame without ever losing focus on the summit itself…but these are my impressions, and I hope each listener will have a different interpretation of the music (which is, after all, more important than any of my ideas about it!).
Stuart MacRae (2003)