Surely the first lesson any aspiring singer learns - well if all those TV talent shows are to be believed - is to try to memorise the lyrics and, if performing a popular modern standard, stick to something resembling the original tune.
Sadly that's what French singer-song writer Daniel Lévi must wish he had done at the July 14 concert for equality organised by the French anti-racist non-governmental organisation SOS Racisme at the foot of the Eiffel Tower in Paris.
The soon-to-be 50-year-old (he was born on August 26, 1961) was just one of a host of French singers to perform live on Bastille day in front of tens of thousands crammed on to the Champs de Mars, and the many millions watching the event live on France 2 television.
A chance for Lévi to shine and show-off that exceptional and powerful voice which won him so much acclaim when he performed as Moses in Pascal Obispo's 2000 musical "Les dix commandements" (The ten commandments).
But it wasn't to be, as Lévi took to the stage with Indonesian-born French singer-songwriter Anggun and Judith, a former contestant on the now-defunct French TV talent show Star Academy.
The trio were to interpret Jean-Jacques Goldman's "Là bas" in a manner which can only be described as awful.
Now, even if you don't like Goldman - and there are plenty who don't - there's no denying the immense talent of the man and the impact he has had over the years on French music.
Many of his songs have become modern French standards and perhaps one that stands out is "Là bas", the 1987 hit he sang with the late Sri Lankan-born British singer Sirima.
It has been covered by many artists throughout the years but no performance can have been quite as embarrassing and appalling as the one provided by Lévi et al in what turned out to be surely the worst rendition - ever.
During the performance the teleprompter reportedly broke, and that - to put it mildly - rather threw Lévi.
The true professional that he clearly wasn't under the circumstances appeared lost without the prompter and, forgetting the lyrics, la-la-la-ed his way through great chunks of the song.
Worse still he was out of tune in both his solos and harmonies and even though he grinned inanely throughout, nobody listening and watching could have been impressed.
Anggun and Judith didn't fare much better, but in comparison to Levi, their voices were tunefully angelic.
If you're feeling exceptionally brave and feel your ears are up to it, then you might - repeat, might - want to click on the link to the video to listen and watch.
Be warned though. It really is terrible.
Perhaps you would be better advised to listen to the original which is, quite simply, beautiful.