Inevitably, a shower of stardust garlanded the launch in Edinburgh yesterday of a massive project that will culminate in a performance in the Usher Hall of the Concerto for Group and Orchestra, written by Jon Lord, founder and former keyboard player in rock group Deep Purple.

Lord, who was playing his signature Hammond organ in the legendary piece in a huge performance in Sao Paulo, Brazil, just two weeks ago, was present at yesterday's launch and is actively involved in preparations for the Edinburgh performance, which will take place on October 5. It is the Scottish premiere of the 40-year old classic.

Lord will also play Hammond in the Edinburgh performance, alongside an extraordinary line-up with a full rock group and full symphony orchestra, with every musician - barring Lord himself - a young music student studying in Scotland.

And that is the point. Despite the glitz and glamour of the occasion in the Usher Hall in October, and despite the fabulous aura that the presence of this rock giant and legend will bring to the event, the project unveiled yesterday is, root and branch, an education project and very probably a unique one at that.

It's a collaborative project that will involve students from every level of music education in the country, from commercial to specialist, and will not so much cross over as smash through perceived barriers between so-called high art and low art.

The man driving this remarkable initiative is Ken Thomson, head of music and drama at Stevenson College, in Edinburgh; and the rationale behind the venture, which might sound rather prosaic, is entirely educational.

"We've been in discussions with John Wallace, principal of the RSAMD in Glasgow, for some time. We do very strong commercial music courses in Stevenson, and the RSAMD is a conservatoire. It was an idea, encouraged by the Scottish Funding Council, to match up the excellence of our rock and jazz performers with that of academy musicians.

"I believe that our commercial musicians should have recognition of the abilities they have at some sort of conservatoire standard. And, since John and the RSAMD made the decision to come on board, we've found that we do have values we can share, working together to combine our courses and activities."

It was a bold plan anyway, to combine rock and classical musicians in a collaborative event. But it needed a big idea and a big project to kick-start the collaboration.

A potentially huge resource was being assembled, as the RSAMD would provide a symphony orchestra, which Thomson would augment with student players from the Edinburgh Schools Symphony Orchestra and the specialist Edinburgh Music School at Broughton. Thomson also had his Stevenson rock specialists itching to get their hands on a meaty project that would give them the opportunity to shine.

Thomson was aware of Jon Lord's Concerto for Group and Orchestra from its premiere at the Royal Albert Hall in 1969, where it was played by the Royal Philharmonic Orchestra and Deep Purple, with the composer Malcolm Arnold conducting, and where, incidentally, featuring in the RPO brass line-up on that historic night 40 years ago, was a rising young trumpeter from Fife by the name of John Wallace.

Anyway, at this point in Thomson's evolving plan, pure Scottish brass neck entered the equation. It seemed fanciful, but wouldn't it be nice to get the imprimatur of the great man himself?

So Thomson fired off an e-mail to Lord's website, outlining his proposal. Within two days Jon Lord was in touch, saying, "Let's talk".

Meanwhile, the project to combine and collaborate was growing arms and legs. Both the RSAMD and Stevenson College have traditional music courses, and it was agreed to combine these forces too, in performance, and Phil Cunningham agreed to come on board as director. Both the college and the academy have jazz resources, so they all went into the pot too.

Stevenson College, cleverly, invited Jon Lord to Prestonfield House Hotel, where, as well as being wined and dined, Lord could sample the music from Stevenson's rock group, which played a medley of extracts from the concerto, a fully-blown concerto in four movements.

The students, recalls Thomson, were "absolutely terrified" at what was effectively an audition. But they must have acquitted themselves well, because the serious talking started.

"Jon has not done anything like this before, so he trod carefully, initially, to see what we were about. He talked about levels of performance, quality of musicianship and artistic awareness. Once he was convinced about that, the lights went to green and we were introduced to his manager and agent.

"I got the impression that he seemed honoured that we were interested in his music to the extent of wanting to present it as a project."

And Stevenson got a bit more than an imprimatur. With Lord taking a specially negotiated fee (or they would never have been able to afford him), Stevenson acquired for their special project the total involvement of Jon Lord - who has already been to the college, coaching the rock band, has been hooked by the educational side of the venture, and who will join the 100-strong orchestra and rock group on stage, bringing his authentic accent and his inimitable Hammond sound to the concerto.

Moreover, he expressed to Thomson a keen interest in traditional music, so a special element will be seeded into the programme where Cunningham and Lord will have a jam session, folk style. Now that's unique.

Additionally, in the first half of the monster programme, the RSAMD and Stevenson jazz bands will combine for a 20-minute session conducted by Thomson himself, while the traditional musicians from conservatoire and college will do the same in a 15-minute slot directed by Cunningham.

Lord's involvement in his concerto is total. "This will not be a thumping rock concert," says Thomson. "Jon's intention is that the sound from the rock musicians will be absorbed into the orchestral sound so that they merge and blend.

"And he's done it so many times that he has this down to a fine art. He is specific and meticulous about how that blend is achieved, and has engaged fully with us on what was clearly a hugely delicate and sensitive process."

The educational significance in the venture is clear and profound, says Thomson.

"This is unique. Stevenson College is combining with the RSAMD, the Edinburgh Schools Symphony Orchestra and the specialist Edinburgh Music School at Broughton. Therefore in one place and at one event in one evening we have all the layers of music education in Scotland represented: school, further education, specialist and higher education.

"We have the whole caboodle. And we have Jon Lord."

There is, of course, only one way to end such a night. Lord, at his beloved Hammond, will lead the massed rock and orchestral forces in an orchestrated performance of the Deep Purple anthem Child in Time.

Jon Lord's Concerto for Group and Orchestra, Usher Hall, October 5, 7.30pm.