Voice competitions attract singers like moths to a flame, but what can they hope to achieve by competing and how great are the dangers of getting their wings burnt? The BBC Cardiff Singer of the World 2015 reaches its Grand Final this weekend, so it’s a good time to reflect on the pros and cons of singing competitions.

Cardiff Singer is one of the most prestigious competitions, with the likes of Karita Mattila (1983) and Anja Harteros (1999) among its winners. In Turkey, the Leyla Gencer Voice Competition, run by the Istanbul Foundation for Culture and Arts, started in 1995. It also boasts some starry winners who have gone on to major international careers. Nino Machaidze (2006) and Pretty Yende (2010) were both winners, while other prizewinners include Marcelo Álvarez and Anita Rachvelishvili, now favourites at houses like the Metropolitan Opera; all notable singers worthy of honouring the Turkish soprano after whom the competition is named.

Another great diva, Joan Sutherland, is honoured in Australia. The Joan Sutherland & Richard Bonynge Award, the finals of which take place in September, is open to singers from Australia and New Zealand, aged between 20 and 30 years old. Prizes are both financial and experiential, such as the chance to perform at Verbier Festival. Plácido Domingo’s Operalia competition, hosted in a different city every year, comes to London in July and is aimed at singers ready to perform on the great international stages. 2010 winner Sonya Yoncheva is now in demand in every major House. Aida Garifullina, 2013 winner, now has a major Decca recording contract.

The pitfalls of winning a major voice competition are elephantine. At worst, they can propel a young singer into a career for which they are not adequately prepared. Record labels dive in – especially when the young singer concerned has marketable glamorous good looks – and launch them on the road to stardom. Major opera houses offer major roles and if the singer crashes and burns… well, there’ ll be another star-in-the-making around the next corner. Some singers fail to make any significant mark on the stage.

Occasionally – just occasionally – a singer will emerge triumphant, absolutely ready for a major career. Dmitri Hvorostovsky, winner of the 1989 Cardiff Singer, stepped straight onto the world’s most prestigious stages and into a lucrative recording contract and is still one of the stars in the operatic firmament.

Audiences at singing competitions are often littered with agents and casting directors, keen to spot the talent. Even if a singer doesn’t walk away with the top prize, it’s arguably these particular audience members who hold the keys to greater riches. For example, Hvorostovsky’s fellow finalist, Bryn Terfel (1989 was dubbed ‘the battle of the baritones’) has had an equally glittering career.

The canny winners are the ones who recognise that their voice is very much ‘work in progress’ and shun the glamorous offers that come their way in order to continue their studies. Romanian soprano Valentina Naforniță won Cardiff Singer in 2011, whilst still in her early twenties. Too soon, said some. Naforniță wisely kept her head down and is now a house singer at the Wiener Staatsoper, where she is quietly refining her craft and avoiding the dangers of early stardom.

Maria Ostroukhova, who won second prize in this year’s London Handel competition, explained in an interview that “if you don’t take risk, you don’t drink Champagne”! She’s right, but those risks need to be calculated. Keenly following the progress of this week’s Cardiff Singer ahead of Sunday’s Grand Final, I’ve been amazed at the number of singers choosing repertoire for which their voices are patently unsuited. Mozart requires a clean, pure technique. If you’re happier dazzling around Rossinian coloratura, give Mozart a wide berth. The Belarusian who chose “Mon coeur s’ouvre à ta voix” has a lovely voice but should have gone with lighter repertoire – more of a boyish Cherubino than a man-eating Dalila.

What we really love about these competitions though is the thrill of hearing a new voice which sets the pulse racing. When Mongolian baritone Amartuvshin Enkhbat launched into Gérard’s “Nemico della patria” from Andrea Chénier (we were denied his aria from Prince Igor on the television relay) the sound of collective jaws hitting the ground could be heard across the world. I’ll be really interested to hear just how big the voice is in St David’s Hall on Sunday evening; on television, it sounded huge. “A voice of bronze and velvet” was a description applied to the great Italian baritone Ettore Bastianini. On first hearing, Enkhbat’s voice shares a lot of vocal similarities. Will he triumph on Sunday? Does it actually matter who wins? Casting directors have probably already made their first approaches…