With the 25th anniversary of the first concert by the National Youth Orchestra of Scotland looming in August, it began preparing last year with a series of profile-raising events.

There was an appearance at the BBC Proms in London, the publication of a biography of NYOS by former TES Scotland editor Colin MacLean and a television documentary about one of its three sister bands, the National Children’s Orchestra of Scotland.

The NYOS new year concerts in Edinburgh and Glasgow started this year’s anniversary celebrations and were the culmination of a week-long winter residential course for its 109 players at Merchiston Castle School, Edinburgh.

There were some fine elements in the orchestral playing, particularly the ability of the musicians to maintain a consistent tonal colour across phrases. It was sad to see such a modest audience in Glasgow to appreciate them.

The Royal Concert Hall, which is normally packed for school concerts, was about a third full, with few young people. Considering the competition for places in NYOS and its sister orchestras, youth was woefully under-represented.

Perhaps the programme seemed scary to the musically less adventurous - it is hard to remember the last time Walton’s Symphony No 1 was played in Scotland - but it was well thought out. It did not overlap with performances given locally by professional orchestras over the past few years and it was well designed to cater for key players.

The transition from Debussy’s La Mer, through Saint-Sa ns’s Cello Concerto No 1 to Walton’s symphony did not exhaust the brass section early in the proceedings, so its contributions in the final movement of Walton’s work came across with the noble bearing and clarity they deserved.

NYOS’s confident principal timpanist and the technically assured string sound contributed a vast amount to the motion and tension in the symphony and the orchestra as a whole did much to realise the work’s moods, especially the cynicism and jocularity in the second movement. The bluesy bending of clarinet notes was a nice and appropriate touch in this piece, which was written in the aftermath of the jazz age.

This was conductor Takuo Yuasa’s fifth appearance with NYOS. He created muted washes of colour in Debussy’s work, rather than the more usual salty seascapes, and had the orchestra simply expand upon the soloist’s musical material, rather than behave belligerently, in the concerto.

I liked some of the imagery conjured up in La Mer: the impression of hazy morning mist in the cellos’ shadowy pre-echo of the flute melody in “From Dawn to Midday on the Sea” and the muted trumpet skimming the orchestral waves like a seabird.

As in the third movement of Walton’s symphony, there was too much grace and not enough focus, though the suaveness of the cello playing and the shading of the music by solo violin, flutes and harps was a pleasure to hear.

NYOS concerts are enhanced by soloists who balance maturity of vision and youthful vigour, as cellist Paul Watkins did for Saint-Sa ns’s concerto.

His opening phrase had a rush of excitement and from this he eased naturally into the smouldering embers and sophistication of what followed.

Watkins made it seem as if the music was emanating from deep inside him. It was one of those rare occasions on which instrument and instrumentalist became one.