A good performance of the Mahler (the Debussy was even better), well played by the orchestra, all of who were under 25. They have a fine string section, especially the violins and cellos, and very good woodwinds and percussion; the horns did not have a great night: playing exposed passages quietly seemed to find them (or the principal) out. I wasn't entirely convinced by the Andante (played second), which apart from the climaxes was played at a bluff mezzo piano. The work is probably my least favourite of Mahler's purely orchestral symphonies, and this was my first hearing of it in concert though I know the work well.
Elder's interpretation was fairly orthodox and it was straightforwardly played but with interesting timbres he conjured, especially from the winds. The three hammer blows were played by a strapping six foot youth with an enormous mallet striking a wooden object (I couldn't see clearly), giving a satisfying fortissimo crash - it wavered slightly the first times he lifted it over his head, so the trombones were in danger of receiving severe blunt force trauma… it certainly jolted a few of the audience, many of whom were parents and siblings of the performers and probably not avid Mahlerians. The subsequent times he picked it up a frisson of tension palpably went through the audience.