The National Youth Orchestra of Scotland sounded very well drilled in the demanding repertoire they tackled in their summer concert at the Glasgow Royal Concert Hall. That was due in no small part to the fact that they had played the programme twice in the previous week, firstly in the Netherlands and then at the Konzerthaus in Berlin.

Such invitations are a measure of both the ambition and the high standing which NYOS now enjoys, the result of a great deal of hard work over the two decades since the orchestra was formed in 1979.

Finding the right conductor is always important and in Sian Edwards they had precisely that. Her palpable enthusiasm and proven abilities provided an ideal combination, and the orchestra responded with some excellent, highly disciplined playing.

NYOS can never be accused of giving its charges an easy time. Their programmes are invariably challenging, and since it does not operate on quite the same commercial restraints as the professional orchestras (although funding remains a perennial problem), it can also afford occasionally to be unorthodox.

That was the case here, at least in terms of choosing to open, rather than close, the programme with a substantial new symphony by the Scottish composer John Maxwell Geddes. He has a proven track record in writing for youthful enembles, but made little concession in his powerful Symphony No 3.

Quite rightly, he treated the orchestra as a highly capable one and stretched its resources in imaginative fashion. The players emerged with flying colours, dispatching the music confidently from the nebulous textures of the opening movement to the rampaging finale.

There was no respite for the orchestra, since the second piece was longer and in some respects even more demanding. Alexander Baillie, the distinguished cello soloist, took the unusual step of introducing Alfred Schnittke’s Cello Concerto No 1, by way of preparing the audience for the emotional intensity of the music, and used amplification to boost the cello, notably for the long ecstatic crescendo of the finale, an ending which is simultaneously majestic and unsettling.

If Baillie faced the most difficult challenges, the players rose to both the technical and expressive demands of the music in dramatic style, and the long silence which followed the final notes (happily not disturbed by premature applause) was a highly charged one.

After a welcome interval, Edwards guided the orchestra through the often virtuoso orchestral scoring of Elgar’s Variations on an Original Theme (the so-called Enigma Variations) with a pleasing lightness of touch. It can hardly be classed as an easy work, but it provided something in the way of lighter relief after the emotional storms which preceded it.