Osmo Vänskä and the Lahti Symphony Orchestra add to their out- standing Sibelius series with this fascinating collection of rarities, centring on The Oceanides. The shorter pieces are often intriguing, too, as recognisable Sibelius fingerprints mingle with ideas that no one would expect from this composer. Taken together, the whole collection offers the most illuminating picture of Sibelius’s creative process, reflecting not so much the austerity we associate with him as his practical musicianship in developing sparks of inspiration.

In 1914 Sibelius worked on no fewer than three forms of the material we have come to know in the final version of The Oceanides. The seeds were sown in the third movement of an orchestral suite which has since lost its first movement. There are theories that the first movement was later developed into the 1913 tone-poem The Bard but the second movement of the suite was later used in a piano piece, To Longing, while the third, under five minutes long, provided material for the two quite different versions of The Oceanides.

Sibelius wrote the Yale version of The Oceanides on a commission from the American university, but no sooner had he delivered the completed score than he began recomposing the whole piece. Curiously, he went back to the original order of the material in the finale of the Suite, but expanded it and refined it out of all recognition. The Yale version, originally called Rondo of the Waves, presents the material in an unexpected order, with what became the main theme set nearer the middle, and with the stormy climax even more of a culmination than in the final version, making the result more dramatic. Only three-quarters the length of the finished version, it is a most effective piece, something that could very well be brought into the regular repertory.

Sibelius has as his main key D flat major, awkward for the strings but bringing tonal subtleties, where the final version is in the more string-friendly key of D major. Surprisingly, he made all these changes without ever hearing any of the versions until the final one. The first two remained unplayed until after his death.

Otherwise, the most substantial work here is the Cassazione, which in this original version of 1904 uses a bigger orchestra than what became Op 6. One can understand the composer’s desire to rework it, given the perfunctory nature of its close, replete with its corny patriotic tune. The Coronation March taken from a cantata celebrating Tsar Nicholas II (not a congenial task for a patriotic Finn) is hardly a march at all, but fun to hear, and the tiny Morceau romantique, written for a charity concert, is a jolly waltz movement using material written by a rich relative of Marshal Mannerheim, later the Finnish President. Spring Song of 1895 is uninhibitedly melodic, and Cortège in a polonaise rhythm is Sibelius working in the light of day, with mystery removed, a bit like some of the Karelia Suite. Apart from the two versions of The Oceanides, this may not be great music, but for any lover of Sibelius it makes compelling listening, helped by masterly performances and beautifully balanced recording.