The Woodnymph is one of Sibelius' early tone poems and while it doesn't hold up against his later works in the genre, it is certainly worth a listen. It is a full scale epic work, lasting over 20 mins, in the grand romantic style with a lot of good tunes and a poweful finale. Not one of his most personal compositions, but very, VERY good. And since this is the only recording of it, it is worth getting before the CD goes out of print.
The disc also features the very short piece A Lonely Ski Trail, which isn't anything spectacular, but very atmospheric.
And then there's the world premiere recording of the complete score to Swanwhite, incidental music to the play of the same name. Pretty low key, but some wonderful things going on, particularly with the woodwinds. Very nice.
Overall I wouldn't call this an ESSENTIAL Sibelius disc, but undoubtedly something for the fan who already has most of Sibelius' major works and wants something new for his/her collection.