It's one of the great clichés that the more successful you are, the more reluctant the public is to let you change. No musician was ever more derided than Bob Dylan when he put down his acoustic guitar in favour of a Strat. There are still plenty around who have never felt the same about Eric Clapton since he left Cream and Radiohead (for all their success) lost a lot of fans when they switched from anthemic complaint-rock to highly-politicised experimentation.

So, you can't help wondering how master guitarist Uli Jon Roth feels when he is billed as 'former Scorpions guitarist' - which he is, all the time. It's not that he has anything to be ashamed of for his stint in the German metal outfit but, damn it, Uli was in the band from 1973-8 - which is getting on for thirty years ago! Since then he has carved out a thoroughly unorthodox career. Three albums were recorded with his own band, Electric Sun, since when he has concentrated his undeniable virtuosity on what is probably best called 'neo-classical rock' - which means he has written, among other things, four symphonies and two concertos. He has toured continuously (memorably working with other illuminati like opera legend Jose Careras and guitarists Joe Satriani and Michael Schenker), he was on the 2002 Legends of Rock UK tour and has released a clutch of albums, leading up to this year's revelatory Metamorphosis.

But, somehow, Uli Roth, for all that he still carries the Scorpions tag, has managed to do the seemingly impossible - he has carried a sizeable number of fans with him, on a remarkable journey of musical (not to mention mystical) exploration.

Why is Metamorphosis so different? Well, not least because it involves Uli playing the lead violin part of Vivaldi's Four Seasons on his six octave electric 'Sky' guitar - not to mention containing a complete new concerto.

Today, Uli Jon Roth lives in Wales - in a castle, naturally - and, what with that and some distinctly cosmic artwork used on his albums and website (you should see the astonishing presentation on the Metamorphosis CD!) you'd be forgiven for expecting a distinctly old hippy conversation. But far from it, in fact. Uli Roth remains very together, very direct and very clear-headed. So much for assumptions.

I began by asking about the rumours surrounding the recording of Metamorphosis. Tales of mysterious equipment failures - all sorts of troubles.

'I wouldn't say they were troubles, so much as obstacles,' he says. 'I needed to find some new answers and finding these answers was what took some time. Mainly, I wanted to find a new balance between orchestra and electric instruments and find something that was an organic whole. Usually when orchestras meet electric players, I'm usually not very satisfied with the result, sonically. Either the orchestra ends-up like a keyboard accompaniment, or the electric instruments sound horribly out of place. It's not so much the playing, but the sounds - they are from two different worlds. That was something I always felt strongly about and it's something I've been trying to find answers to for many years. I think I've finally got to that point now and I'm really satisfied with the result.

'I ended-up going to quite extraordinary lengths, making sure I'd got the microphone placings right, for example using six or seven different mics simultaneously and three different rooms simultaneously, and this together with the right musical approach finally gave me the result I was looking for.'

Metamorphosis was recorded digitally, at Uli's own studio, through an Oram 40 channel desk, using 128 channels of Soundscape and the orchestra was also recorded there, but in sections, rather than trying to record the entire orchestra simultaneously (which, presumably, would have called for a much larger recording area).

'This particular projects started as a live recording,' Uli says. 'Originally the Four Seasons was recorded with a German orchestra a couple of years ago and that was live, but I wasn't too happy with certain technical aspects - for example we used drums and the percussion sound was bleeding through all the mics, so I started re-recording the orchestra at home to get better separation and the result was good, so I ended-up re-recording the whole lot, and the same with the guitar, although we've kept the live feel.'

That is certainly obvious from the sound, which is very ambient. No doubt this is partly down to the use of the three large rooms at the front of Uli's house, which gives him something like a 30 metre ambience - so it was bye-bye Lexicon on this recording - everything is down to natural room reverb, with each string section being recorded by up to ten different mics, using adjacent rooms to give extra ambience.'

Given the amount of studio time involved and the huge costs it would incur, does Uli think he could ever take Metamorphosis on the road?

'It's thoroughly possible, yes. I mean we've been invited to do the Vivaldi several times and usually the cost of an orchestra is prohibitive, even if its a chamber orchestra, but for a special occasion you can do it and there will be more of that in the future.'

Proving that I'm as capable of asking a predictable question as anyone, I ask Uli what it was that steered him away from head-on Rock to neo-classical. 'Oh, that was so long ago. Ever since I was 17, I wanted to write a violin concerto and symphonic music. So back then I started to get the technical equipment - the mental technical equipment - to be able to do these things. Back then, I didn't know anything about score-writing, proper counterpoint and so on and, yes, I was in a Rock band, but in my spare time, my heart was always in classical music and that's where I drew my inspiration from, apart from my obvious leanings to the music of Jimi Hendrix. Gradually, it began to crystallise. In the 1980s I started to write larger pieces; my first guitar concerto, a one and a half hour piece, and then project followed project and doing something like the Vivaldi on the guitar just seemed to be part of that road.'

Going back to the opening of this story, I asked Uli how his fans had reacted to Metamorphosis. Was there any bad reaction from those who wanted him to return to hardcore Rock?

'No, in fact it is probably my best-received album so far and the reviews have been good - usually around 9/10. It's so far off the beaten track, so far out there, that it's kind of hard to categorise. And when you're talking about my fans, you're talking about people who are used to me going off on tangents. Every album is something they didn't expect'.

UJR (as his fans known him) isn't the first to have drawn inspiration from the linear, metrical, contrapuntal nature of Baroque music and there are clear connections between, say, the melodic simplicity and purity of ideas expressed in what is called 'early music' and what we call Rock and Pop. Similarly, you'd have to be deaf not to hear counterpoint at work in a lot of heavy metal. Does Uli see this a natural marriage between these two musical forms separated by three hundred or so years?

'It's the road I've chosen and I'm getting a lot of inspiration from the old masters and I want to pursue that path.' he says.. 'If you ask me about other people, I do detect that there are more and more musicians going down a similar route. I suppose it will always be a more elitist thing, because you can't just pick up the guitar and do these things - you need complete skills or it will be a botched job - just horrible. But for me, I thrive on these challenges.

'And this isn't entirely new,. Don't forget, in the early 1970s there was Keith Emerson doing all sorts of things - Pictures at an Exhibition and so on'.

So, would he agree that there is an essential connection between Rock and the Baroque style?

'Well, there is... and it's an interesting question. There are certainly some neo-classical players who have been leaning in that direction, a friend of mine, Yngwie Malmsteen, is one of them, and I guess there are similarities. There is a certain angularity to baroque music that is there in Rock music, too. Though, I'm not so much a baroque type myself, though I do love Bach. Personally, I'm more coming from the Romantic angle. Early classical music is, for me, perhaps a little too rigidly structured, because I like to find new ways of balancing large forces in the music - the classical Romantic composers like Franz Liszt have done a lot to invent new musical forms.'

This is a fascinating reply - maybe it's a guitarist thing? Jimmy Page has said much the same in the past when asked about a proposed guitar orchestra project which, sadly, never materialised. UJR, too, is pulled in this direction, so watch out for touches of Mahler, Wagner Lizst and Chopin and in future projects!

While none of this would be impossible with in ordinary guitar, Uli's choice of his seven string, six octave 'Sky Guitar' is the perfect tool for this master player. Designed by Roth himself, it was made by the sometime Brighton-based Greek luthier Andy Demetriou, who has, sadly, stopped making guitars, since.

It is, by any standards, a remarkable instrument - not least because it has scalloped frets (concave dips in the fingerboard between each fret). How had that come about?

'I didn't originally have that on the guitar, but I did it to enable me to have better access with the pick at the top end. Because the neck is so very long, extending well into the picking area, I found that with the earlier Sky guitar, I didn't have deep enough access into the string with the pick, so I saw Ritchie Blackmore had his scalloped and I thought maybe we should do it on these three frets in the picking area. And once we did it, I liked it so much that I had it done on the entire playing area.'

Historically, Uli has had three six string and two seven strings Sky guitars, with the seventh string, a bass string, not used on the Vivaldi, but audible on Metamorphosis.

And that incredible sustain? That's thanks to John Oram's active pickups, with virtually 90dB output (a Strat has under 10dB, Uli says). This allied to a gain as well as a volume control enables Uli to regulate the gain and distortion he is getting, allowing him to get an amazing singing tone, even at relatively low volumes. And for amp nuts? Metamorphosis was recorded using a 20 Watt custom-built Sky Amp (made in the USA), which he describes as a cross between a Marshall and a Vox. You can hear this on the first half of the Vivaldi piece, he says. It's coupled with the output of a Vox AC30, 'Which, sadly, I'm always blowing to bits,' he sighs. 'I used both of my AC30s and blew them up three times each, while making the album. I just managed to finish the recording, then went on tour and blew them up again. I think the output of the guitar is just too much - apparently the new ones are better and I must check them out. The third amplifier I used was my old Scorpions Marshall from 1972. If you measure that amp, it produces 140 Watts before clipping and you can hear that carrying a lot of the sound on the Metamorphosis - it's a bigger sound than the one I used on the Vivaldi.'

And the mics for this amazing guitar recording? Think ultimate quality. You're right Neumann U47 for distant guitar micing, U67, for warmth on guitar, add a dash of U87 and you have it. And the strings? Uli has recently added two brand new John Oram valve mics to his collection and speaks very well of them.

And there you have it. An amazing recording by an amazing guitarist. And a very nice man.

Ends.