Behind every good musician up on stage is a good roadie. They fetch and carry, mend, improvise, set up instruments, beaver away – no set hours of course, no National Union of Road Managers (yet). What they know they've largely taught themselves, or picked up along the way.

There are roadies and roadies; humpers and technicians. That's not to put any job down, but in the organisation of a big tour, with the money available today, there's obviously a lot of specialised work involved to get the whole show on in the first place. I'm sure the major artists would admit (if they'd admit to anything) their debt to the road crew. Who are they, and what exactly do they do, apart from covering the stage with gaffer tape and shouting "one, two' into the mike?

Alan Rogun is a specialist roadie, usually only responsible for the band's guitars, and well known west of Ealing and at Shepperton in particular where he's worked for The Who for many years with his partner Bill Harrison.

I put it to him that being a roadie was as important a job in the whole show as the punk on stage may be performing, but that the very term "roadie" is in itself somewhat demeaning. "Yeah, everyone thinks it's a sweaty, overweight guy with long hair and a T-shirt. I personally blame all the T-shirt manufacturers: they're a bunch of rich arseholes who give them away to bribe people cheaply, and all my antique collection of T-shirts are up for sale, including this one."

Seriously though, how d'you get into it (the job, not the T-shirt) is the classic backstage question Alan has been asked many times. He, like many other roadies, played guitar and only took on crewing on a part-time basis. Obviously playing helps, but it's not vital, he admitted. Working initially for a hire company which he found more interesting than for a single band ("less politics"), Alan was offered a Who tour in 1975 which he reckoned would be about three weeks' work. Nine years later, he's still closely associated with Pete Townshend and John Entwistle and has also worked with the Rolling Stones, Eric Clapton and Joe Walsh amongst others.

Starting weeks before rehearsals, Alan will begin setting up the required guitars, cleaning the frets lightly with a fine steel wool and using a little linseed or lemon oil on the ebony and rosewood fretboards. Maple has to be treated more carefully, so as to avoid discolouration. When stringing up the guitar he doesn't put a lock in as he may need to remove the string quickly.

Pete Townshend will use one type of guitar and have ten spares, varying only in colour. I've seen them in the studio all lined up and shining like soldiers on parade. As Alan put it, "After working with Pete, everything else is a doddle," adding that "Pete is the best, he really relies on you." Although he can be quite a gentle chap offstage, Mr T is different on stage. Some of the famous smashing scenes may be put down to bad temper (remember the famous scene in "Blow Up", Antonioni's movie, where they got Jeff Beck to do what Pete should have done), but at one point Pete found it annoying that even if The Who played a bad gig, the kids would be perfectly happy as long as he smashed his axe up. Pete has used various guitars – Fenders, Gibson SGs and more recently Roger Giffin/Schecter models. He gave up on the Fenders as they proved too hard to smash up. Alan carried all the spare parts and spare necks he needs on tour with him in a huge flight case and patches the guitars up as he goes along. This is probably the origin of the old Who motto, "Always have a spare for the spare."

Alan likes to keep the sound set-up as basic as possible. If a fault develops it's traceable down from the guitar through the jack plug and pedals to the amplifier. He sees a lot of it as common sense and attention to detail. If possible, as Alan did with the Stones, he likes to have twice as much equipment on stage as needed; above all, never try to mend anything on the spot, he advises.

Previous to the Rolling Stones 1981 tour Alan had never worked with the band, so that was a new experience for him. How's Keith Richard to work with? "A gent," says Alan. And Ronnie Wood? "Easier, as long as he has something to strum!" That shouldn't be too difficult with 18 to 20 guitars to look after on the tour (although he didn't have to string every one up for each show). Alan was impressed not with what Keith puts in, but what he leaves out. "That and his interplay with Charlie is superb; he's definitely in charge out there and although people say he's only got three licks, I've never seen someone use those licks so many times in so many different ways." Mick played guitar too on that tour and it was he who played hardest and broke the most strings; still, he sings well so that's probably a good excuse. In the US the Stones rehearsed the music (but not the stage sound) in a barn in Massachusetts, moving straight to JFK Stadium in Philadelphia – a 90,000 seater. A few adjustments in the opening numbers were all they needed to balance the sound. That and of course all those years of experience in playing those gigs together.

Surely, I ventured, there's room for a little fun too? Alan then began telling me of John Entwistle's birthday party on the 1976 Who tour; the first time he'd seen the normally laid back John "go at it" with Pete, and he didn't mean eating extra jelly and ice cream, or musical chairs. Basically they proceeded to put the entire hotel room, partitions and all, out of the window and into the pool below. Pete was about to jump in himself, but realising the joke would be over once he was cold and wet, he didn't. Must be hard work breaking up hotel rooms.

"Never believe tour itineraries," Alan says. "If it states 'day off' they're omitting to tell you you're travelling 17 hours on a bus at 55mph and at the end of it you have seven hours to sleep in."

Alan rates Eric Clapton as the greatest player; he says he knows this for a fact. Joe Walsh is a player who knows exactly what he wants, whether it's in regard to the guitar, amp or whatever. In his case Alan doesn't need to suggest which guitar could best produce which sound. Working in a studio is of course very different to being on tour. When recording Alan may have to bring every amplifier and guitar along and service them ready for possible use.

Finally, Alan mentioned the stability that well-known and reliable faces can give to a band. "If Stu wasn't there, the Stones would panic. Likewise it's been so with Bob Pridden and The Who, and to a lesser extent myself and Bill Harrison," he said, adding that Pete Townshend had nonetheless always encouraged him to tour with other bands so that he could keep up with whatever new was happening.

However good you are technically – and obviously that's very important – it appears to me that in order to do a good job you must have your head screwed on and really know how to deal with sometimes temperamental musicians who are maybe hopped up by adrenalin or whatever. In other words "you may have to put up with a lot of shit" in order to reach a position of some responsibility like Alan Rogun. "But no matter what you do," he says, "don't kid yourself you'll never be replaced – because you will."