Taking over a concert at short notice and making a success of it is still one of the best ways of creating an impact, and the young Danish conductor Thomas Søndergård was clearly up for the task as he replaced the BBC National Orchestra of Wales's indisposed principal conductor Thierry Fischer on the St David's Hall podium. Fischer wasn't the only casualty of the night though: Schönberg's Op 21 Variations for Orchestra, a cornerstone of the original programme, were jettisoned in favour of Sibelius's symphonic poem, En Saga, a Søndergård party-piece by the look of it.

Forget Scandinavian cool, Søndergård is hot-blooded and quite a mover, though more of a wiggler than a shaker. His dynamic approach was very much to the liking of the BBCNOW players, who willingly turned up the heat in response, the strings in particular. The Sibelius had plenty of character with Alex Thorndike's viola solos adding to the atmosphere of the dramatic narrative. Meanwhile, Brahms's Fourth Symphony had passion but, apart from a truly Beethovenian scherzo with the timpani (Søndergård's original instrument) ensuring a hard rhythmic edge, the work as a whole was curiously lacking in the emotional and structural insight needed to make it a memorable interpretation.

It was in accompanying soloist Roderick Williams in Mahler's song-cycle, Lieder Eines Fahrenden Gesellen, that Søndergård showed his real credentials, balancing textures and moods with a deft touch. And even if Williams's expressive baritone could not encompass the extremities of the songs' range with his usual authority, every word was articulated so that they carried the palpable pain of the youth who is betrayed in love.