The Swedish virtuoso Gunnar Idenstam tells us that he has toyed with the idea of arranging Debussy’s La mer for organ ever since his student days. Having tried out various passages over the years, ‘each time I have returned the [score and piano reduction] to the cupboard thinking it just can’t be done’. Idenstam’s doubts were understandable and, sadly, justified; for while one can only applaud the ingenuity of his transcription and the extraordinary technique needed to play it, I think La mer is one of those works that do not transfer to another medium. The Stahlhuth/Jann organ of the Eglise Saint-Martin de Dudelange, Luxembourg, is a powerful symphonic instrument supplying all the orchestral colours you could wish for (it has particularly lovely flutes, solo clarinet and punchy reed chorus) but the harp (especially in ‘Jeux de vagues’), percussion and string pizzicato are such important elements of Debussy’s palette that the organ simply cannot reproduce their role to comparable effect.

To a lesser extent the same problem besets La valse. Too often the basic pulse is obscured (the cathedral rumble of a 32- or even 16-foot pedal doesn’t provide the necessary pinpoint definition) and the final pages, so thrilling in their orchestral, piano solo or two-piano versions, are here merely sonically awesome. How Idenstam’s left hand maintains the side drum’s role for the nearly 16 minutes of Boléro is something to wonder at. The inexorable crescendo is skilfully graded but again at the climax – the famous key-change – the spine fails to tingle. For me, the two wholly successful transcriptions are ‘Lever du jour’ and the Pavane. Despite my reservations, these should not deter organ aficionados from savouring a programme of rich ambition and imagination.