One of the more gratifying daydreams I have is to wonder what would happen if there were some kind of mix-up at Broadcasting House, and I ended up in the Desert Island Discs studio talking about myself with Kirsty Young, instead of talking about the latest Jennifer Aniston film with Mark Lawson. Although, to be fair, I am also talking about myself on Front Row. I just pretend I’m there to review the film.

Picking songs would be both stressful and fun, which is my favourite kind of activity. But after Nick Park’s appearance on the programme last week, it has gained a new dimension: nepotism. Park included a song by an unsigned musician from Sheffield, Joe Rose, whose iTunes sales promptly shot through the roof. So far, so Christmas miracle – the song is lovely, Rose comes across as adorable, and the programme did what it’s supposed to do, at least in part: introduce an audience to something they didn’t already know.

But the backlash was Grinchily swift – Park turns out to be a friend of Rose’s parents. What had been a sweet story of an unknown musician getting a seasonal boost became a story about a famous person giving a friend a leg-up. But the question that none of Park’s critics seemed willing to ask, let alone answer, is what is wrong with liking the music of a friend. And why shouldn’t you plug it?

Elvis Costello and Bob Dylan, who Park also chose, don’t need him as their champion. But Rose is starting out in an industry that is already stacked against virtually everyone involved in it. Earlier this month, The Word published a survey which found that 60% of pop acts in the charts had been to public school. Twenty years ago, it was 1%. There was a great deal of muttering in the press about Hooray Henrys taking over the world (first Downing St, now HMV), with little thought as to why the figures are unsurprising.

Musicians not only don’t get paid when they start out, they often have to pay to perform. Open mic nights can and do demand that each band brings ten paying guests with them. If they don’t, they have to find that ticket money themselves. And if they don’t want to play a gig on those terms (and who in their right mind would?), that’s tough: there are hundreds of other acts who will.

The music industry – like almost all media careers – has closed its doors to those who don’t have family money. If you want to work in television or publishing, you need to be able to work an unpaid internship for several months, before you even begin the merry-go-round of perpetual short-term contract work and job-hunting. The internship will probably be in London, where rents are stratospherically high, even in the more murderous areas.

So if you don’t happen to have wealthy parents and/or a rent-free address in central London (some internships don’t even offer you your travel expenses), you are pretty much ruled out. The fact that those people overlap closely with people who went to public school can hardly come as a surprise.

Songwriters rival children’s book authors for unsustainable earnings – 90% of PRS members earn less than £5,000 a year. Our idea of the rewards inherent in these professions is hopelessly skewed by the big names. But those big names are rarely new to their business: the music trade paper, Pollstar, released its list of highest-earning live tours this week. Virtually every artist in the top ten was already successful when I was at school – Bon Jovi, AC/DC, Metallica, U2. Only two artists of them had begun their music careers in the past decade – Michael Bublé and the mighty Gaga.

So with so much to dissuade young musicians from getting started in the business at all, I find I can live really easily with Nick Park’s plug. Now, if you’ll excuse me, I have to get back to my song selection. Tom Waits’ San Diego Serenade, obviously. But then what?