Lara Trump is one of life’s tougher cookies, as anyone who saw her introducing her father-in-law at the Republican convention will testify.

That confidence will come in handy this week if Lara dares to gauge reaction to her latest venture - becoming a pop star. It would seem that if the Trumps can’t get the actual Taylor Swift to back Donald, they’ll produce their own Tay Tay.

Well, the reviews are in, and they are not pretty.

“Sounds like a wild hog and a sack of rusty cans being thrown into an industrial wood chipper,” said a sampler of Lara’s new single, Hero.

“Every note is a violation of the Geneva Convention,” observed another.

One pet-loving critic said his dogs begged him to set fireworks off rather than play the song again.

The reaction to Hero is a reminder that everyone loves to watch a good old-fashioned takedown by the critics. Everyone except the victim, that is. There is an earlier version of the critic’s art on show in a new movie out next week. Adapted by Patrick Marber from the novel by Anthony Quinn, The Critic stars Ian McKellen as Jimmy Erskine, the reviewer of the title, and Gemma Arterton as Nina, an actress who often bears the brunt of his wrath.

“Over the last ten years you’ve compared me to livestock, creatures of the sea and an extinct bird. It’s going to stop,” says Nina.

“Oh,” says Erskine, “are you retiring?”

At 85 and with a career still going strong, tumbles from the stage aside, McKellen has had a lifetime of encounters with critics.They are “generally civil when their inaccuracies are corrected”, he writes in his blog. “But I’ve avoided arguing with them when they seem to have missed or not approved of the point of a production or performance. Actors are used to criticism, every day from directors, more valuable than a critic’s judgement based on one viewing at a first night.”

Not everyone is so relaxed. “I don’t envy the job of the critic,” says writer-producer Colm Tobin. “Imagine earning your daily crust by publicly unpicking the work of people who are baring their soul to the world in whatever field - be it music, theatre, dance, mime, puppetry, comedy or even Morris dancing. I’d rather work in an abattoir.”

As a former film critic who now earns a crust writing about TV, I have been on the other side of the fence. The grass is not as green as the critics of critics imagine. Yes, you get to see the big movies before anyone else and spot a few stars in the making along the way. But I’ve also spent many hours watching absolute mince. I have stared into the abyss and found Norbit, Scottish Mussel, Basic Instinct 2 and many other crimes against cinema, staring back at me.

At such times, a critic can be tempted to go for the jugular. Part of it is simple annoyance; you will never get those hours back again. There is also the thought that the poor reader, if not alerted to the danger ahead, might go out and spend their hard-earned on this rubbish.

Some of the most vicious hatchet jobs come about because writing them is fun. Every now and then there comes a takedown so unhinged all one can do is stand aside and enjoy the spectacle of a critic losing it, like Basil Fawlty with his broken-down car.

The late AA Gill’s review of Morrissey’s Autobiography remains a classic of the takedown genre. The author, wrote Gill, “is plainly the most ornery, cantankerous, entitled, whingeing, self-martyred human being who ever drew breath. And those are just his good qualities”.

It was Gill who said the historian Mary Beard “really should be kept away from cameras altogether”. It was a cruel, sexist thing to say but in the resulting furore, Gill came off worse. Beard was deluged with offers to write books and present more programmes. A star was born.

By simply highlighting someone’s work a critic can make as well as break. Ask any up-and-coming performer at Edinburgh festival time if they would like a critic to come along to their show and the hand holding the Biro will be bitten off.

There will always be more negative reviews than positive ones because standout material is rare. If everyone is given a four or five star review, how will anyone be able to distinguish between works? Go and see for themselves is one answer, but see above about cost.

It is not only the people involved in a production who take exception to a lukewarm review. I once had a reader demand I be sacked because he disagreed with my verdict on The Darjeeling Limited. That’s Wes Anderson’s films for you. Another movie loved by audiences and hated by almost every critic was Mamma Mia! What can I say? The hackles were up from the moment critics clocked that exclamation point.

Most critics would consider themselves on the side of the reader. They have to justify their reviews, to themselves, an editor, the audience, and sometimes the person whose work is being reviewed.

Jay Rayner, MasterChef judge, Observer restaurant critic and author (new book, Nights Out at Home, out now) says he doesn’t feel guilty about the harsher reviews.

“I don’t because I don’t do it lightly, and I don’t think you should ever do it lightly, you should pick your targets very carefully. I live by a single rule: punch up, not down. There is no point in kicking 10 tonnes of crap out of a small, family-run restaurant that’s failing – they’re going to fail all by themselves.

“But if a big, over-financed corporate, glossy place that’s charging £20 a starter and £45 a main course and it’s not delivering for that money, I don’t hesitate to say so.”

Ian McKellen’s character in The Critic does not doubt his worth to the public and his publisher alike. “I’m the critic. I have power and influence,” he says.

But, notably, The Critic is set in 1930s London, long before the internet came along and made everyone a critic. While McKellen’s character would be horrified by such democratisation of the trade there is no going back now. Moviegoer356 and Foodfanatic24 have as much right to throw their tuppence worth in as any critic. And they don’t expect any payment.

Jimmy Erskine would give that idea a one-star review for sure.

The Critic is in cinemas from 13 September