To suggest that the National Youth Orchestra of Scotland is on a roll this summer, right through July and dipping into August, risks understatement.

After all, the classical limbs of the umbrella NYOS organisation have already given orchestral concerts in Perth Concert Hall last Friday and Edinburgh's Greyfriars Kirk this Wednesday, while, at the same time, the NYOS Jazz Orchestra has been on the road, touring to Skye, Nairn and Stirling, where it finishes its summer blast tonight at The Tollbooth.

All this, across the musical spectrum, forms a runway to three enormous symphony concerts that, with the events already mentioned, amount to a huge celebration of the 35th anniversary of NYOS, the parent organisation charged with nurturing the cream, the very best, of this country's top young musicians from all the airts and pairts, and all walks of life, in both musical and in broad social and community terms.

That is one heck of a responsibility; and there will be opportunities to judge how well that responsibility has been acquitted over these three big concerts, effectively a tour, beginning at The Sage in Gateshead on Wednesday, July 30, as part of the European Youth Orchestra Festival, moving to the Three Choirs Festival for a performance in Worcester on Friday, August 1, and then up to Edinburgh's Usher Hall for a grand 35th anniversary gala concert on Saturday, August 2, at 7.30pm.

The musical demands on the youngsters throughout the anniversary programme are, as you might expect of the best of the best, ambitious and challenging. They will open with an overture by William Walton (tricky), follow that with Sally Beamish's demanding Trumpet Concerto, played by the great trumpeter Hakan Hardenberger, and conclude with the almighty Romantic epic by Richard Strauss, An Alpine Symphony, where Strauss's own demands are little short of preposterous.

The awesome and majestic symphonic poem, which itself is 100 years old next year, does what it says on the label. It begins in night, deep in the dark belly of the orchestra, and ends there, returned to night and shrouded in blackness. In between you will hear the determined tread at the beginning of an assault on the mountain, the perilous ascent to the summit by a solo oboe, tentatively picking his way to the top, and the incandescent blaze of the music at the summit, which will pin you to your seat. You will hear all manner of vicissitudes, from icy slopes to a glacier; from a waterfall to a deafening, thunderous storm, and six minutes of the most gorgeous music ever written as the light begins to fade.

It's an incredible masterpiece of graphic pictorialism. It requires a huge orchestra (including organ). There will be 120 young NYOS musicians on stage (and off). Conductor Michael Francis will direct an armoury of brass, a battalion of percussion and a full division of woodwinds and horns. If you don't know it, the Alpine will blow you away. If you do know it, it ain't around that often, so don't miss it. Not coming to Glasgow, folks: come on through. (I'll be there, with the crampons, the hot sugary tea and the hip flask for the cold bits.)

Seriously, the event, and the entire summer touring programme, is emblematic of a revitalisation, restructuring and new confidence that has been generated in the NYOS since the appointment of Joan Gibson as chief executive in 2012. NYOS funding by Creative Scotland, slashed in a period of uncertainty and dubious management, has been restored, embracing the jazz arm. Everything's been rebranded and brought into one organisation. There's a new orchestra, NYOS Junior Orchestra (age eight to 13), a NYOS Senior Orchestra (11-18) and "big NYOS" as it is known colloquially (from 13 up to 25). There is NYOS Camerata, the chamber orchestra, which will be playing next month, and NYOS Futures, the contemporary music limb, with admission to the latter two ensembles by invitation. There is a new consistency and continuity, with a fresh sense of purpose and direction. It's all to play for. Roll on that gala.