Doping is not just the preserve of suspiciously muscular Tour de France cyclists and incredibly swift sprinters but also, it seems, earnest frock-coated musicians playing Brahms and Liszt on the world’s best concert podiums.

“Between 25 and 30 per cent of musicians regularly take tablets or alcohol to combat performance anxiety,” says Helmut Möller, head of Berlin’s Kurt Singer Institute for Musical Health. Almost paralysed by stage fright, many musicians - and Professor Möller is not talking about Amy Winehouse or the usual suspects from the rock scene - guzzle beta-blockers, medication usually prescribed for heart problems.

Substance abuse among concert musicians has been going on for decades but has been kept under wraps. Unlike drugs taken in competitive sport, the self-medication of highly strung musicians is not about cheating or winning unfairly but about avoiding mistakes caused by a nervous twitch or a sudden lapse in concentration. The problem came to light when a horn player from the Berlin Philharmonic confessed in a new documentary film to needing drink before performing.

“You go for tranquillisers or beer,” says Klaus Wallendorf, “with me it was beer.” His teacher advised him to drink a beer if he could not reach a note. “Then you drink two beers and it goes smoothly so you think you should do it all the time, “ said Mr Wallendorf, speaking in Thomas Grube’s film Tour of Asia which accompanies the Philharmonic and its chief conductor, Sir Simon Rattle, on a ground-breaking 2005 tour.

The confession has triggered a debate in the German musical world. Other horn players admitted to a drinking problem. The tenor Roland Wagenführer said that he was seriously worried about the use of drugs by opera singers.

Even the British violinist Nigel Kennedy, on tour in Germany, chipped in to the debate, declaring that cocaine and marijuana are “as popular among my colleagues as in other social circles.” His main objection was that “drugs lead to half-dead performances - beta-blockers, tranquillisers - they may stop you making mistakes but they don’t do much besides.”

Claudia Spahn, Professor of Psychosomatic Medicine at Freiburg University, says that there is now a black market in beta-blockers in the orchestra pits. “The player next to you may know someone who can get it, or a relative with a heart problem can get the stuff put on his prescriptions,” she says.

Brilliant musicians as diverse as the cellist Pablo Casals and the pianists Arthur Rubinstein and Glenn Gould, as well as the baritone Dietrich Fischer-Dieskau, were seriously afflicted by stage fright. The tenor Caruso suffered until the end of his career, and contemporaries remember that he always smelt of orange essence, which he believed would calm his nerves.

Gerald Mertens, head of the 9,000-strong German orchestral association, is urging music academies to teach not only notation and technique but also relaxation strategies.

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