Is Ryanair taking musicians for a ride?

My friend has a sticker on her cello case which reads: "NO, I DON'T WISH I PLAYED THE FLUTE". The inconvenience of lugging around this outsized contraption is the price cellists pay for making possibly the most beautiful sound ever created by humankind. The size is trumped only by the double bass. My college next-door neighbour played one. I wondered why she chose it, since she was even shorter than I am, until I noticed that whenever she returned from a rehearsal, a different man would be carrying the bass for her.

But the difficulty of travelling with a musical instrument has recently got a whole lot worse. Latest target: violinists. Violins fit comfortably into aeroplanes' overhead compartments. Some airlines accept them in supplement to the hand-luggage allowance. Ryanair, though, now demands that an extra seat is purchased for a violin.

Last week the Incorporated Society of Musicians took up the cause of Francesca Rijks, a 12-year-old violin student from Chetham's School of Music in Manchester, travelling home from Germany with her father on Ryanair. They checked in unimpeded, but were stopped at the gate and ordered to pay £190 (more than their seats had cost) for carrying the violin, despite apparently having been assured in advance that they could take it on board. And in the time it took to buy the violin's ticket, the plane left without them.

The ISM's legal spokesman, David Abrahams, said: "The idea that musicians should be forced to purchase an additional seat on board an aircraft because they are carrying an instrument that can be stored safely in the overhead lockers is unfair, discriminatory and irrational."

In August, reports appeared about three violinists travelling from Frankfurt to perform in Norfolk. Just days before their flight, Ryanair allegedly demanded £1,340 for their violins. The concert promoter, Norfolk Concerts, is reportedly preparing legal action against the airline. Meanwhile, Ryanair says that its policy is consistent.

If you look at the website, it is. But its application in these cases sounds frankly chaotic. The Facebook group Musicians against Ryanair, encouraging a boycott of the airline, has attracted nearly 13,000 members. Some users on there describe being forced to put instruments in the hold, where they were wrecked. Some recount buying a seat for a violin, then being instructed to stow it in the overhead compartment. Others allege that the policy's application is akin to bullying, extortion or, er, being on the fiddle.

Some people assume musicians demand "special treatment" by wanting the right to carry instruments on board. Actually, it's the reverse: they are seeking the same treatment as anyone else obliged to take a plane to do a contracted job. Stringed instruments are critically damaged by extreme temperatures or incautious handling: mostly they're not only ruined by hold travel, but can't be insured for it. That's not "preciousness", it's a fact – and airlines need to take this on board.

If Ryanair's policy spreads, the knock-on effect on the music industry will be catastrophic: touring costs, already soaring, will become prohibitive and this very travel-dependent and financially volatile sphere will be dealt a death blow.

I heard last week that the leader of a major international orchestra, faced with fiddle-on-board problems while travelling long-distance to London to play in a Prom, proved such a "force to be reckoned with" (a mutual friend's description) that staff let him through. Musicians are sadly accustomed to being bullied, many having been through the mill at school. Standing up to bullies is a skill requiring cultivation. It's time musicians stopped having to apologise for their profession.

Airlines need to be clear about their musical instrument policies. As for musicians, they should check those policies before booking and be ready to stick up for their rights. Meanwhile, my six-year-old nephew is starting cello lessons. I wonder if he knows what he's letting himself in for.