Speculation about Ronnie Scott's death is focusing on his loss of `embouchure'. Nicholas Roe meets John Cobb (right) who suffered a similar blight 30 years ago but who has lived to tell the tale
When the jazz musician Ronnie Scott died last week a curious fact emerged from the sad confusion surrounding his end: this vastly experienced musician had been depressed by the loss of something most of us might be tempted to smile at because it sounds silly and we know so little about it: his "embouchure".

The word describes the crucial shaping of lips on the mouthpiece; it is a contortion of muscles - simple, but vital. Yet can any of us really understand what that loss means?

John Cobb knows. His own musical life was blighted by precisely the same affliction as Scott's, despite the efforts of a psychiatrist and even a hypnotist. By an odd quirk of fate, Cobb's career also came to an end last week, though under happier circumstances.

Just before Christmas he said goodbye to fellow members of the London Philharmonic Orchestra, from which he was retiring after more than 25 years' service. The great and the good came to the farewell bash, including the conductor Bernard Haitink, yet the strange truth is that Cobb barely played a note during his time with the orchestra. Though he was once a gifted trombonist, the role he played with the LPO was as personnel manager.

What happened? "I can talk about it now," Cobb explains at his home in Thames Ditton, Surrey, "but it's strange, I find myself getting tense even after all these years. How can I describe it? One day your whole future has gone. Your whole life seems to drop away. And it's all because of some stupid little muscular thing. It's very frightening."

That "stupid little muscular thing" - Scott's, and Cobb's - is not common in the musical world, but it's not rare either. With Scott it followed operations on his teeth, with Cobb the cause was more subtle and mysterious, though just as devastating. Musicians who lose their embouchure can still whack out a tune - but some passages will defeat them, or some sounds. The quality will go; the distinctive, personal tone.

Cobb's career began so promisingly. His father was a butcher and brass- band master. Cobb himself might have gone into the meat trade but heard a trombone one day and was entranced: "I found the melodies so beautiful," he says. He shakes his head. "I can't really explain."

He just joined the Central Band of the Royal Air Force and for eight years played in countless parades until, aged 26, he won a scholarship to the Royal College of Music. The professor there was also musical director of the Royal Opera House at Covent Garden and when Cobb qualified he was promptly hired for the pit.

So now the butcher's boy was playing for the greatest performers in the world. One old programme, now framed, for 10 June 1958, features the names Joan Sutherland, Maria Callas and Margot Fonteyn. "The atmosphere was electric," Cobb enthuses. "It was so exciting. I remember going to rehearsals and thinking, `This is just beyond me.' But then you realise that the other players are human too and your confidence grows."

It grew for eight happy years as Cobb developed the orchestral musician's crucial feel for team creativity. He talks about "superb moments" when Dennis Brain played off-stage horn in Wagner's Ring cycle. He describes tricky but exciting work: "Maybe there's a chord with three trombones playing together and someone has difficulty getting in so a colleague blows that little bit louder to give you a chance to pick up ..." He adds, "I would get a thrill every time I went through the stage door."

The rot began with delicate insidiousness. They were recording The Flying Dutchman at Walthamstow Town Hall and Cobb had a bit of trouble with a short solo: "I was not very happy with it and then it started to become a little bit problematic, getting the thing played. It couldn't have been that bad because they wouldn't have let it through. But it was noticeable to me."

He struggles to explain."It isn't a pain. It's just that it doesn't grip the mouthpiece properly. The muscles are developed to grip and suddenly they aren't doing their job." Ask why and he struggles even more. He was an obsessive player, and insecure. Where others would rehearse in the morning then rest before an evening's performance, Cobb would take the trombone home and play again. He took it away on holiday. "Maybe I did too much," he concedes. "Maybe I was obsessed. Maybe I had to do it to keep up."

Cobb is witty and intensely level-headed. There is no whiff of oddity about him. And yet things got worse. Perhaps the fact that his wife was at this stage diagnosed as having cancer played a part. He really doesn't know.

He went to the Royal Middlesex Hospital where a doctor - "I suppose he must have been a psychiatrist" - said that nervousness was affecting muscle control. The bizarre outcome was that Cobb spent two months lugging his trombone into the consulting room to play, lonely notes echoing round the wards.

He was taught how to relax, yet it proved impossible to recreate - and thus deal with - the tensions of actual performance. When that doctor emigrated, Cobb turned instead to a hypnotist, again without success.

Meanwhile there were crucial moments of difficulty in the pit. The musical camaraderie saved him for a while: he would nudge fellow trombonists when facing panic at a difficult passage and they would cut in while Cobb sat there, trombone glued uselessly to his lips. "The thing I loved most I began to hate," he says. "None of us wants to be a failure. When panic starts your breath control goes, you can't maintain a constant flow of air. It isn't the loud bits that bother you, it's when you have to have control, when the conductor looks over, puts his hand down and you have to produce something. It's very lonely."

After eight months of struggling he quit, toured as a freelance, did a bit of teaching, fretted; he had two young children to support. "The instrument gave me up," he laughs. "I bluffed my way through but there was no real living there."

So, an unseasonal story of personal decline? Actually, no, and that farewell party explains why. Cobb thought about what he might salvage from the wreckage, about the things he loved about music: musicians, friendship, touring, excitement, the sounds. And he took a job as assistant personnel manager to the London Symphony Orchestra: "I just wanted a job to push myself in another direction." Eventually he took over as personnel manager at the Bournemouth Symphony Orchestra and finally, in 1970, joined the London Philharmonic from which he finally retired last week.

He says, "I was so fortunate. I had a wonderful, wonderful time and I was able to enjoy my working life so much." And music? Oddly, there have been half-a-dozen occasions over the years when Cobb has had to pick up the trombone again because of lateness or sickness in the orchestra. He managed; says he wasn't very good, but then that was perhaps the attitude which caused him such trouble in the first place.

Five years ago he bought a new trombone. Now he is playing again and in retirement hopes to join a big swing band. The pressure's off. Cobb's playing for fun. Watch out for him; and give him a big hand